Comparative Analysis of Predictive Biomarkers for PD-1/PD-L1 Inhibitors in Cancers: Developments and Challenges

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

Usefulness of the Early Increase of Peripheral Blood Lymphocyte Count in Predicting Clinical Outcomes for Patients with Advanced Hepatocellular Carcinoma Treated with Durvalumab Plus Tremelimumab

BACKGROUND/OBJECTIVES

Durvalumab plus Tremelimumab (Dur/Tre) therapy is expected to have good therapeutic efficacy for patients with advanced hepatocellular carcinoma (HCC). However, the predictors of clinical response and prognosis have not been established. Here, we retrospectively investigated the predictors for therapeutic response and clinical prognosis of Dur/Tre therapy.

METHODS

This retrospective single-center study, which included 30 patients, aimed to evaluate predictors of treatment efficacy of Dur/Tre therapy for advanced HCC. Factors associated with an objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and immune-mediated adverse events (imAEs) were examined. We especially focused on the initial change in peripheral lymphocyte count at 2 weeks after Dur/Tre introduction from baseline (Δlymphocyte).

RESULTS

Seventeen patients (56.7%) diagnosed with HCC BCLC stage C were enrolled. The median observational period was 11 months. The ORR and disease control rate (DCR) were 30.0% and 53.3%, respectively. The median PFS was 3.7 months and OS was not reached. The high Δlymphocyte was an independent predictor of objective response (hazard ratio [HR], 1.004; p = 0.016). The high Δlymphocyte (above +245/µL) was an independent predictive factor for better PFS (HR, 0.308; 95% CI, 0.095-0.998; p = 0.049), and the median PFS was significantly prolonged in the high Δlymphocyte (above +245/µL) compared to low Δlymphocyte (less than +245/µL) (not reached vs. 1.96 months, log-rank p = 0.003).

CONCLUSIONS

In Dur/Tre therapy, the early increase in peripheral blood lymphocyte count was useful for predicting clinical response and prognosis.

Analysis of mutually exclusive expression in cancer cells identifies a previously unknown intergenic regulatory paradigm

Mutual exclusion of gene expression has received limited attention. Gene (expression) plasticity analysis provides an efficient way to identify highly plastic genes (HPGs) based on changes in expression rank. In this study, we quantitatively measured the expression plasticity of 19 961 protein-coding genes in 24 human cancer cell lines and identified HPGs in these cells. By comparing methods, we showed that virtual sorting and cosine similarity, rather than Pearson and Spearman rank correlations, are suitable for mutual exclusion. Mutually exclusive gene pairs were identified in each cell type. Experimental validation showed that thiol methyltransferase 1B (TMT1B; also known as METTL7B) and CD274 molecule (CD274; also known as PD-L1) were mutually exclusively expressed at either the mRNA or protein level. METTL7B negatively regulated PD-L1 expression in several cell types, and the JAK/STAT3 pathway was involved. Knockdown of METTL7B in Huh7 cells inhibited interleukin 2 (IL-2) secretion by Jurkat cells in co-culture experiments, and the inhibition was blocked by anti-PD-L1 antibodies. Therefore, this study provides an efficient method of expressional mutual exclusion and implies a newly identified intergenic regulatory paradigm.

Unraveling Th subsets: insights into their role in immune checkpoint inhibitor therapy

T helper (Th) cell subsets play pivotal roles in regulating immune responses within the tumor microenvironment, influencing both tumor progression and anti-tumor immunity. Among these subsets, Th1 cells promote cytotoxic responses through the production of IFN-γ, while Th2 cells and regulatory T cells (Tregs) exert immunosuppressive effects that support tumor growth. Th9 and Th17 cells have context-dependent roles, contributing to both pro-inflammatory and regulatory processes in tumor immunity. Tumor antigen-specific T cells within the tumor microenvironment often exhibit a dysfunctional phenotype due to increased expression of inhibitory receptors such as CTLA-4 and PD-1, leading to reduced antitumor activity. Monoclonal antibodies that block these inhibitory signals-collectively known as immune checkpoint inhibitors (ICIs)-can reactivate these T cells, enhancing their ability to target and destroy cancer cells. Recent advancements have highlighted the critical role of T helper subsets in modulating responses to ICIs, with their interactions remaining a focus of ongoing research. Both positive and negative effects of ICIs have been reported in relation to Th cell subsets, with some effects depending on the type of tumor microenvironment. This review summarizes the crucial roles of different T helper cell subsets in tumor immunity and their complex relationship with immune checkpoint inhibitor therapy.

In-silico analysis unveiling the role of cancer stem cells in immunotherapy resistance of immune checkpoint-high pancreatic adenocarcinoma

Although immune checkpoint (IC) inhibition is a major treatment modality in cancer-immunotherapy, multiple cancers show low response. Our in-silico exploration by mining cancer datasets using R2, available clinical trial data, and Kaplan-Meier analysis from GEPIA depicted that unlike low-responder (LR) cancers, high-responder (HR) cancers furnish higher IC expression, that upon lowering may provide better prognosis. Contrastingly, pancreatic adenocarcinoma (PAAD) demonstrated high IC expression but low immunotherapy-response. Infiltration scores from TIMER2.0 revealed higher pro-tumor immune subsets and cancer-associated fibroblasts (CAFs) while depicting lower anti-tumor immune subsets in PAAD as compared to HR lung adenocarcinoma (LUAD). Additionally, bioinformatic tool cBioportal showed lesser tumor mutational burden, mismatch repair deficiency and greater percent of driver mutations in TP53, KRAS and CDKN2A in PAAD, supporting its higher immunotherapy-resistance than LUAD. Our search for the 'key' immunotherapy response-deciding factor(s) revealed cancer stem cells (CSCs), the known contributors of therapy-resistance and immuno-evasion, to be positively correlated with above-mentioned driver mutations, pro-tumor immune and CAF subsets; and that PAAD furnished higher expression of CSC genes than LUAD. UMAP/tSNE analyses revealed that high CSC signature is positively correlated with immunotherapy-resistance genes and pro-cancer immune cells, while negatively with cytotoxic-T cells in PAAD. Our in-silico study explains the low immunotherapy-response in high IC-expressing PAAD, wherein CSC plays a pivotal role. Further exploration portrayed correlation of CSCs with immunotherapy-resistance in other LR and HR cancers too, substantiating the need for personalized CSC evaluation and targeting for successful immunotherapy outcomes.

Prognostic Significance and Molecular Classification of Triple Negative Breast Cancer: A Systematic Review

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer defined by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression. Despite accounting for 15-20% of all breast cancer cases, TNBC is associated with poor prognosis and a high likelihood of recurrence and metastasis. Understanding the molecular subtypes of TNBC is important for developing targeted therapies and improving patient outcomes. This systematic review aimed to assess the prognostic significance of molecular subtypes of TNBC and the implications for therapeutic management. A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, and Web of Science, to identify studies focusing on the molecular classification of TNBC and its prognostic relevance. Studies were included based on specific inclusion criteria, including original research evaluating clinical outcomes and survival data in molecularly classified TNBC cohorts. Data were extracted, synthesized, and analyzed to determine the prognostic implications of different TNBC subtypes. The review identified several distinct molecular subtypes of TNBC, including basal-like, mesenchymal, immune-modulatory, and luminal androgen receptor (LAR) subtypes. Basal-like TNBC was associated with poor prognosis and high rates of recurrence, while immune-modulatory TNBC exhibited better survival outcomes, particularly in patients with high levels of tumor-infiltrating lymphocytes. Mesenchymal and LAR subtypes exhibited diverse clinical behavior and varying therapeutic responses. Furthermore, key prognostic biomarkers, such as BRCA1/2 mutations and programmed death-ligand 1 expression, were highlighted which have therapeutic implications. Molecular classification of TNBC provides valuable prognostic information and guides therapeutic strategies. Integrating molecular subtyping into clinical decision-making will be essential for the development of personalized treatments and improved outcomes for TNBC patients. However, further research is needed to refine classification systems and address existing therapeutic gaps in TNBC management.

Changes in L-phenylalanine concentration reflect and predict response to anti-PD-1 treatment combined with chemotherapy in patients with non-small cell lung cancer

Chemotherapy combined with checkpoint blockade antibodies targeting programmed cell death protein (PD-1) has achieved remarkable success in non-small cell lung cancer. However, few patients benefit from long-term treatment. Therefore, biomarkers capable of guiding the optimal therapeutic selection and reducing unnecessary toxicity are of pressing importance. In our research, we gathered serial blood samples from two groups of non-small cell lung cancer patients: 49 patients received a combination of therapies, and 34 patients went under chemotherapy alone. Utilizing non-targeted metabolomic analysis, we examined different metabolites' disparity. Among the lot, L-phenylalanine emerged as a significant prognostic marker in the combination treatment of non-small cell lung cancer patients, interestingly absent in patients under sole chemotherapy. The reduced ratio of L-phenylalanine concentration (two-cycle treatment vs. pre-treatment) was associated with improved progression-free survival (hazard ratio = 1.8000, 95% confidence interval: 0.8566‒3.7820, p < 0.0001) and overall survival (hazard ratio = 1.583, 95% confidence interval: 0.7416‒3.3800, p < 0.005). We further recruited two validation cohorts (cohort 1: 40 patients and cohort 2: 30 patients) to validate the sensitivity and specificity of L-phenylalanine prediction. Our results demonstrate that a model based on L-phenylalanine variations could serve as an early risk-assessment tool for non-small cell lung cancer patients undergoing treatment, potentially facilitating strategic clinical decision-making.

Production of novel theranostic nano-vector based on superparamagnetic iron oxide nanoparticles/miR-497 targeting colorectal cancer

Colorectal cancer (CRC) is a serious public health concern worldwide. Immune checkpoint inhibition medication is likely to remain a crucial part of CRC clinical management. This study aims to create new super paramagnetic iron oxide nano-carrier (SPION) that can effectively transport miRNA to specific CRC cell lines. In addition, evaluate the efficiency of this nano-formulation as a therapeutic candidate for CRC. Bioinformatics tools were used to select a promising tumor suppressor miRNA (mir-497-5p). Green route, using Fusarium oxyporium fungal species, manipulated for the synthesis of SPION@Ag@Cs nanocomposite as a carrier of miR-497-5p. That specifically targets the suppression of PD1/PDL1 and CTLA4pathways for colorectal therapy. UV/visible and FTIR spectroscopy, Zeta potential and MTT were used to confirm the allocation of the miR-497 on SPION@Ag@Cs and its cytotoxicity against CRC cell lines. Immunofluorescence was employed to confirm transfection of cells with miR-497@NPs, and the down- regulation of CTLA4 in HT29, and Caco2 cell lines. On the other hand, PDL1 showed a significant increase in colorectal cell lines (HT-29 and Caco-2) in response to mir497-5p@Nano treatment. The data suggest that the mir-497 -loaded SPION@Ag@Cs nano-formulation could be a good candidate for the suppression of CTLA4in CRC human cell lines. Consequently, the targeting miR-497/CTLA4 axis is a potential immunotherapy treatment strategy for CRC.

Biomarkers for immunotherapy resistance in non-small cell lung cancer

Immunotherapy has revolutionised the treatment landscape of non-small cell lung cancer (NSCLC), significantly improving survival outcomes and offering renewed hope to patients with advanced disease. However, the majority of patients experience limited long-term benefits from immune checkpoint inhibition (ICI) due to the development of primary or acquired immunotherapy resistance. Accurate predictive biomarkers for immunotherapy resistance are essential for individualising treatment strategies, improving survival outcomes, and minimising potential treatment-related harm. This review discusses the mechanisms underlying resistance to immunotherapy, addressing both cancer cell-intrinsic and cancer cell-extrinsic resistance processes. We summarise the current utility and limitations of two clinically established biomarkers: programmed death ligand 1 (PD-L1) expression and tumour mutational burden (TMB). Following this, we present a comprehensive review of emerging immunotherapy biomarkers in NSCLC, including tumour neoantigens, epigenetic signatures, markers of the tumour microenvironment (TME), genomic alterations, host-microbiome composition, and circulating biomarkers. The potential clinical applications of these biomarkers, along with novel approaches to their biomarker identification and targeting, are discussed. Additionally, we explore current strategies to overcome immunotherapy resistance and propose incorporating predictive biomarkers into an adaptive clinical trial design, where specific immune signatures guide subsequent treatment selection.

Evolving Treatment Landscape of Frontline Therapy for Metastatic Urothelial Carcinoma: Current Insights and Future Perspectives

Cisplatin-based chemotherapy has long been the standard first-line (1L) treatment for metastatic urothelial carcinoma (mUC). However, up to 50% of patients with mUC may be ineligible for cisplatin owing to comorbidities, necessitating alternative primary treatment options. Immune checkpoint inhibitors (ICIs) have emerged as a vital alternative for those unable to receive cisplatin. Nevertheless, the prognosis of advanced UC remains dire and challenges persist in optimizing 1L therapy. Recent medical advancements have redirected attention towards innovative drug combinations for the primary treatment of mUC. The combination of enfortumab vedotin (EV) and pembrolizumab has shown significantly improved overall and progression-free survival rates compared to those with chemotherapy alone. This combination can be used as a 1L treatment for patients with mUC who are cisplatin-ineligible or require alternatives to standard chemotherapy. While platinum-based chemotherapy continues to be essential for many patients, the approval of EV and pembrolizumab as 1L treatments for cisplatin-ineligible patients signifies a major breakthrough in primary cancer care. These therapies offer enhanced outcomes in terms of survival and response rates and highlight the increasing relevance of ICI-containing regimens in frontline cancer care. This review provides an exhaustive overview of the current frontline treatment landscape of mUC and explores new therapeutic strategies, with the aim of facilitating clinical decision-making and guiding therapeutic strategies in patients with mUC.

PD-1 blockade plus cisplatin-based chemotherapy in patients with small cell/neuroendocrine bladder and prostate cancers

Small cell neuroendocrine cancers share biologic similarities across tissue types, including transient response to platinum-based chemotherapy with rapid progression of disease. We report a phase 1b study of pembrolizumab in combination with platinum-based chemotherapy in 15 patients with stage III-IV small cell bladder (cohort 1) or small cell/neuroendocrine prostate cancers (cohort 2). Overall response rate (ORR) is 43% with two-year overall survival (OS) rate of 86% (95% confidence interval [CI]: 0.63, 1.00) for cohort 1 and 57% (95% CI: 0.30, 1.00) for cohort 2. Treatment is tolerated well with grade 3 or higher adverse events occurring in 40% of patients with no deaths or treatment cessation secondary to toxicity. Single-cell and T cell receptor sequencing of serial peripheral blood samples reveals clonal expansion of diverse T cell repertoire correlating with progression-free survival. Our results demonstrate promising efficacy and safety of this treatment combination and support future investigation of this biomarker. This study was registered at ClinicalTrials.gov (NCT03582475).

The Importance of Predictive Biomarkers and Their Correlation with the Response to Immunotherapy in Solid Tumors-Impact on Clinical Practice

Background/Objectives: Immunotherapy has changed the therapeutic approach for various solid tumors, especially lung tumors, malignant melanoma, renal and urogenital carcinomas, demonstrating significant antitumor activity, with tolerable safety profiles and durable responses. However, not all patients benefit from immunotherapy, underscoring the need for predictive biomarkers that can identify those most likely to respond to treatment. Methods: The integration of predictive biomarkers into clinical practice for immune checkpoint inhibitors (ICI) holds great promise for personalized cancer treatment. Programmed death ligand 1 (PD-L1) expression, tumor mutational burden (TMB), microsatellite instability (MSI), gene expression profiles and circulating tumor DNA (ctDNA) have shown potential in predicting ICI responses across various cancers. Results: Challenges such as standardization, validation, regulatory approval, and cost-effectiveness must be addressed to realize their full potential. Predictive biomarkers are crucial for optimizing the clinical use of ICIs in cancer therapy. Conclusions: While significant progress has been made, further research and collaboration among clinicians, researchers, and regulatory institutes are essential to overcome the challenges of clinical implementation. However, little is known about the relationship between local and systemic immune responses and the correlation with response to oncological therapies and patient survival.

The current landscape of spatial biomarkers for prediction of response to immune checkpoint inhibition

Enabling the examination of cell-cell relationships in tissue, spatially resolved omics technologies have revolutionised our perspectives on cancer biology. Clinically, the development of immune checkpoint inhibitors (ICI) has advanced cancer therapeutics. However, a major challenge of effective implementation is the identification of predictive biomarkers of response. In this review we examine the potential added predictive value of spatial biomarkers of response to ICI beyond current clinical benchmarks.

Emerging Therapeutic Strategies to Overcome Drug Resistance in Cancer Cells

The rise of drug resistance in cancer cells presents a formidable challenge in modern oncology, necessitating the exploration of innovative therapeutic strategies. This review investigates the latest advancements in overcoming drug resistance mechanisms employed by cancer cells, focusing on emerging therapeutic modalities. The intricate molecular insights into drug resistance, including genetic mutations, efflux pumps, altered signaling pathways, and microenvironmental influences, are discussed. Furthermore, the promising avenues offered by targeted therapies, combination treatments, immunotherapies, and precision medicine approaches are highlighted. Specifically, the synergistic effects of combining traditional cytotoxic agents with molecularly targeted inhibitors to circumvent resistance pathways are examined. Additionally, the evolving landscape of immunotherapeutic interventions, including immune checkpoint inhibitors and adoptive cell therapies, is explored in terms of bolstering anti-tumor immune responses and overcoming immune evasion mechanisms. Moreover, the significance of biomarker-driven strategies for predicting and monitoring treatment responses is underscored, thereby optimizing therapeutic outcomes. For insights into the future direction of cancer treatment paradigms, the current review focused on prevailing drug resistance challenges and improving patient outcomes, through an integrative analysis of these emerging therapeutic strategies.

Immunotherapy in melanoma: advances, pitfalls, and future perspectives

Cutaneous melanoma is the deadliest and most aggressive form of skin cancer owing to its high capacity for metastasis. Over the past few decades, the management of this type of malignancy has undergone a significant revolution with the advent of both targeted therapies and immunotherapy, which have greatly improved patient quality of life and survival. Nevertheless, the response rates are still unsatisfactory for the presence of side effects and development of resistance mechanisms. In this context, tumor microenvironment has emerged as a factor affecting the responsiveness and efficacy of immunotherapy, and the study of its interplay with the immune system has offered new promising clinical strategies. This review provides a brief overview of the currently available immunotherapeutic strategies for melanoma treatment by analyzing both the positive aspects and those that require further improvement. Indeed, a better understanding of the mechanisms involved in the immune evasion of melanoma cells, with particular attention on the role of the tumor microenvironment, could provide the basis for improving current therapies and identifying new predictive biomarkers.

Development of a microcantilever-based biosensor for detecting Programmed Death Ligand 1

The ongoing global concern of cancer worldwide necessitates the development of advanced diagnostic and therapeutic strategies. The majority of recent detection strategies involve the employment of biomarkers. A critical biomarker for cancer immunotherapy efficacy and patient prognosis is Programmed Death Ligand 1 (PD-L1), which is a key immune checkpoint protein. PD-L1 can be particularly linked to cancer progression and therapy response. Current detection methods, such as enzyme-linked immunosorbent assay (ELISA), face limitations like high cost, time consumption, and complexity. This study introduces a microcantilever-based biosensor designed for the detection of soluble PD-L1 (sPD-L1), which has a specific association with PD-L1. The biosensor utilizes anti-PD-L1 as the sensing layer, capitalizing on the specific binding affinity between anti-PD-L1 and sPD-L1. The presence of the sensing layer was confirmed through Atomic Force Microscopy (AFM) and contact angle measurements. Binding between sPD-L1 and anti-PD-L1 induces a shift in the microcantilever's resonance frequency, which is proportional to the PD-L1 concentration. Notably, the resonance frequency shift demonstrates a robust linear relationship with the increasing biomarker concentration, ranging from 0.05 ng/ml to 500 ng/ml. The detection limit of the biosensor was determined to be approximately 10 pg/ml. The biosensor demonstrates excellent performance in detecting PD-L1 with high specificity even in complex biological matrices. This innovative approach not only provides a promising tool for early cancer diagnosis but also holds potential for monitoring immunotherapy efficacy, paving the way for personalized and effective cancer treatments.

CXCR6-positive circulating mucosal-associated invariant T cells can identify patients with non-small cell lung cancer responding to anti-PD-1 immunotherapy

BACKGROUND

Mucosal-associated invariant T (MAIT) cells have been reported to regulate tumor immunity. However, the immune characteristics of MAIT cells in non-small cell lung cancer (NSCLC) and their correlation with the treatment efficacy of immune checkpoint inhibitors (ICIs) remain unclear.

PATIENTS AND METHODS

In this study, we performed single-cell RNA sequencing (scRNA-seq), flow cytometry, and multiplex immunofluorescence assays to determine the proportion and characteristics of CD8+MAIT cells in patients with metastatic NSCLC who did and did not respond to anti-PD-1 therapy. Survival analyses were employed to determine the effects of MAIT proportion and C-X-C chemokine receptor 6 (CXCR6) expression on the prognosis of patients with advanced NSCLC.

RESULTS

The proportion of activated and proliferating CD8+MAIT cells were significantly higher in responders-derived peripheral blood mononuclear cells (PBMCs) and lung tissues before anti-PD-1 therapy, with enhanced expression of cytotoxicity-related genes including CCL4, KLRG1, PRF1, NCR3, NKG7, GZMB, and KLRK1. The responders' peripheral and tumor-infiltrating CD8+MAIT cells showed an upregulated CXCR6 expression. Similarly, CXCR6+CD8+MAIT cells from responders showed higher expression of cytotoxicity-related genes, such as CST7, GNLY, KLRG1, NKG7, and PRF1. Patients with ≥15.1% CD8+MAIT cells to CD8+T cells ratio and ≥35.9% CXCR6+CD8+MAIT cells to CD8+MAIT cells ratio in peripheral blood showed better progression-free survival (PFS) after immunotherapy. The role of CD8+MAIT cells in lung cancer immunotherapy was potentially mediated by classical/non-classical monocytes through the CXCL16-CXCR6 axis.

CONCLUSION

CD8+MAIT cells are a potential predictive biomarker for patients with NSCLC responding to anti-PD-1 therapy. The correlation between CD8+MAIT cells and immunotherapy sensitivity may be ascribed to high CXCR6 expression.

Beyond PD(L)-1 Blockade in Microsatellite-Instable Cancers: Current Landscape of Immune Co-Inhibitory Receptor Targeting

High microsatellite instability (MSI-H) derives from genomic hypermutability due to deficient mismatch repair function. Colorectal (CRC) and endometrial cancers (EC) are the tumor types that more often present MSI-H. Anti-PD(L)-1 antibodies have been demonstrated to be agnostically effective in patients with MSI-H cancer, but 50-60% of them do not respond to single-agent treatment, highlighting the necessity of expanding their treatment opportunities. Ipilimumab (anti-CTLA4) is the only immune checkpoint inhibitor (ICI) non-targeting PD(L)-1 that has been approved so far by the FDA for MSI-H cancer, namely, CRC in combination with nivolumab. Anti-TIM3 antibody LY3321367 showed interesting clinical activity in combination with anti-PDL-1 antibody in patients with MSI-H cancer not previously treated with anti-PD(L)-1. In contrast, no clinical evidence is available for anti-LAG3, anti-TIGIT, anti-BTLA, anti-ICOS and anti-IDO1 antibodies in MSI-H cancers, but clinical trials are ongoing. Other immunotherapeutic strategies under study for MSI-H cancers include vaccines, systemic immunomodulators, STING agonists, PKM2 activators, T-cell immunotherapy, LAIR-1 immunosuppression reversal, IL5 superagonists, oncolytic viruses and IL12 partial agonists. In conclusion, several combination therapies of ICIs and novel strategies are emerging and may revolutionize the treatment paradigm of MSI-H patients in the future. A huge effort will be necessary to find reliable immune biomarkers to personalize therapeutical decisions.

High CTLA-4 transcriptomic expression correlates with high expression of other checkpoints and with immunotherapy outcome

Background

CTLA-4 impedes the immune system's antitumor response. There are two Food and Drug Administration-approved anti-CTLA-4 agents - ipilimumab and tremelimumab - both used together with anti-PD-1/PD-L1 agents.

Objective

To assess the prognostic implications and immunologic correlates of high CTLA-4 in tumors of patients on immunotherapy and those on non-immunotherapy treatments.

Design/methods

We evaluated RNA expression levels in a clinical-grade laboratory and clinical correlates of CTLA-4 and other immune checkpoints in 514 tumors, including 489 patients with advanced/metastatic cancers and full outcome annotation. A reference population (735 tumors; 35 histologies) was used to normalize and rank transcript abundance (0-100 percentile) to internal housekeeping gene profiles.

Results

The most common tumor types were colorectal (140/514, 27%), pancreatic (55/514, 11%), breast (49/514, 10%), and ovarian cancers (43/514, 8%). Overall, 87 of 514 tumors (16.9%) had high CTLA-4 transcript expression (⩾75th percentile rank). Cancers with the largest proportion of high CTLA-4 transcripts were cervical cancer (80% of patients), small intestine cancer (33.3%), and melanoma (33.3%). High CTLA-4 RNA independently/significantly correlated with high PD-1, PD- L2, and LAG3 RNA levels (and with high PD-L1 in univariate analysis). High CTLA-4 RNA expression was not correlated with survival from the time of metastatic disease [N = 272 patients who never received immune checkpoint inhibitors (ICIs)]. However, in 217 patients treated with ICIs (mostly anti-PD-1/anti-PD- L1), progression-free survival (PFS) and overall survival (OS) were significantly longer among patients with high versus non-high CTLA-4 expression [hazard ratio, 95% confidence interval: 0.6 (0.4-0.9) p = 0.008; and 0.5 (0.3-0.8) p = 0.002, respectively]; results were unchanged when 18 patients who received anti-CTLA-4 were omitted. Patients whose tumors had high CTLA-4 and high PD-L1 did best; those with high PD-L1 but non-high CTLA-4 and/or other expression patterns had poorer outcomes for PFS (p = 0.004) and OS (p = 0.009) after immunotherapy.

Conclusion

High CTLA-4, especially when combined with high PD-L1 transcript expression, was a significant positive predictive biomarker for better outcomes (PFS and OS) in patients on immunotherapy.

Adjuvant Nivolumab versus Ipilimumab in Resected Stage III/IV Melanoma: 5-Year Efficacy and Biomarker Results from CheckMate 238

PURPOSE

In the phase III CheckMate 238 study, adjuvant nivolumab significantly improved recurrence-free survival (RFS) and distant metastasis-free survival versus ipilimumab in patients with resected stage IIIB-C or stage IV melanoma, with benefit sustained at 4 years. We report updated 5-year efficacy and biomarker findings.

PATIENTS AND METHODS

Patients with resected stage IIIB-C/IV melanoma were stratified by stage and baseline programmed death cell ligand 1 (PD-L1) expression and received nivolumab 3 mg/kg every 2 weeks or ipilimumab 10 mg/kg every 3 weeks for four doses and then every 12 weeks, both intravenously for 1 year until disease recurrence, unacceptable toxicity, or withdrawal of consent. The primary endpoint was RFS.

RESULTS

At a minimum follow-up of 62 months, RFS with nivolumab remained superior to ipilimumab (HR = 0.72; 95% confidence interval, 0.60-0.86; 5-year rates of 50% vs. 39%). Five-year distant metastasis-free survival (DMFS) rates were 58% with nivolumab versus 51% with ipilimumab. Five-year overall survival (OS) rates were 76% with nivolumab and 72% with ipilimumab (75% data maturity: 228 of 302 planned events). Higher levels of tumor mutational burden (TMB), tumor PD-L1, intratumoral CD8+ T cells and IFNγ-associated gene expression signature, and lower levels of peripheral serum C-reactive protein were associated with improved RFS and OS with both nivolumab and ipilimumab, albeit with limited clinically meaningful predictive value.

CONCLUSIONS

Nivolumab is a proven adjuvant treatment for resected melanoma at high risk of recurrence, with sustained, long-term improvement in RFS and DMFS compared with ipilimumab and high OS rates. Identification of additional biomarkers is needed to better predict treatment outcome. See related commentary by Augustin and Luke, p. 3253.

Safety and efficacy of immunotherapy plus chemotherapy as neoadjuvant treatment for patients with locally advanced gastric cancer: a retrospective cohort study

BACKGROUND

The combined use of programmed death receptor-1 (PD-1) inhibitors and chemotherapy has reshaped the treatment landscape of advanced or metastatic gastric cancer (GC). This study aimed to assess the efficacy and safety of PD-1 inhibitors combined with chemotherapy in a neoadjuvant setting for locally advanced GC (LAGC).

METHODS

Patients diagnosed with clinical stage II-III GC undergoing neoadjuvant PD-1 inhibitors plus chemotherapy were enrolled from December 2019 to July 2022. Clinicopathological characteristics, pathological information, and survival data were recorded and analyzed.

RESULTS

A total of 42 eligible patients were enrolled, of whom 37 (88.1%) had clinical stage III disease. All the patients underwent surgery, and the R0 resection rate was 90.5%. Major pathological response (MPR) and pathological complete response (pCR) rates were 42.9% and 26.2%, respectively. The overall TNM downstaging rate was 76.2%. A total of 36 (85.7%) patients received adjuvant chemotherapy. With a median follow-up of 23.1 months, four patients died after tumor recurrence, and three were alive with recurrence. The 1-year overall survival (OS) and disease-free survival (DFS) rates were 94.4% and 89.5%, respectively, and the median OS and DFS were not reached. Neoadjuvant treatment was well tolerated with no grade 4-5 treatment-related adverse events (TRAEs) observed. The most common grade 3 TRAEs were anemia and alanine aminotransferase increase (n = 2 each, 9.6%).

CONCLUSIONS

PD-1 inhibitors plus chemotherapy demonstrated promising efficacy, with encouraging pCR and survival outcomes in a neoadjuvant setting for patients with LAGC. The combined therapy also showed a good safety profile.

Functional binding of PD1 ligands predicts response to anti-PD1 treatment in patients with cancer

Accurate predictive biomarkers of response to immune checkpoint inhibitors (ICIs) are required for better stratifying patients with cancer to ICI treatments. Here, we present a new concept for a bioassay to predict the response to anti-PD1 therapies, which is based on measuring the binding functionality of PDL1 and PDL2 to their receptor, PD1. In detail, we developed a cell-based reporting system, called the immuno-checkpoint artificial reporter with overexpression of PD1 (IcAR-PD1) and evaluated the functionality of PDL1 and PDL2 binding in tumor cell lines, patient-derived xenografts, and fixed-tissue tumor samples obtained from patients with cancer. In a retrospective clinical study, we found that the functionality of PDL1 and PDL2 predicts response to anti-PD1 and that the functionality of PDL1 binding is a more effective predictor than PDL1 protein expression alone. Our findings suggest that assessing the functionality of ligand binding is superior to staining of protein expression for predicting response to ICIs.

Biomarkers and factors in small cell lung cancer patients treated with immune checkpoint inhibitors: A meta-analysis

OBJECTIVE

The aim of this meta-analysis was to summarize the available results of immunotherapy predictors for small cell lung cancer (SCLC) and to provide evidence-based information for their potential predictive value of efficacy.

METHODS

We searched PubMed, EMBASE, Web of Science, The Cochrane Library, and ClinicalTrials (from January 1, 1975 to November 1, 2021). The hazard ratios (HR) and its 95% confidence intervals (CIs) and tumor response rate of the included studies were extracted.

RESULTS

Eleven studies were eventually included and the pooled results showed that programmed cell death ligand 1 (PD-L1) positive: objective response rate (ORR) (relative risk [RR] = 1.39, 95% CI [0.48, 4.03], p = 0.54), with high heterogeneity (p = 0.05, I²  = 56%); disease control rate [DCR] (RR = 1.31, 95% CI [0.04, 38.57], p = 0.88), with high heterogeneity (p = 0.04, I²  = 75%); overall survival (OS) (HR = 0.89, 95% CI [0.74, 1.07], p = 0.22); and progression-free survival (PFS) (HR = 0.83, 95% CI [0.59, 1.16], p = 0.27), with high heterogeneity (p = 0.005, I²  = 73.1%). TMB-High (TMB-H): OS (HR = 0.86, 95% CI [0.74, 1.00], p = 0.05); PFS (HR = 0.71, 95% CI [0.6, 0.85], p < 0.001). Lactate dehydrogenase (LDH) >upper limit of normal (ULN): OS (HR = 0.95, 95% CI [0.81, 1.11], p = 0.511). Asian patients: OS (HR = 0.87, 95% CI [0.72, 1.04], p = 0.135); White/Non-Asian patients: OS (HR = 0.83, 95% CI [0.76, 0.90], p < 0.001). Liver metastasis patients: OS (HR = 0.93, 95% CI [0.83, 1.05], p = 0.229); PFS (HR = 0.84, 95% CI [0.67, 1.06], p = 0.141). Central nervous system (CNS) metastasis patients: OS (HR = 0.91, 95% CI [0.71, 1.17], p = 0.474); PFS (HR = 1.03, 95% CI [0.66, 1.60], p = 0.903).

CONCLUSION

The available research results do not support the recommendation of PD-L1 positive and TMB-H as predictors for the application of immune checkpoint inhibitors (ICIs) in SCLC patients. LDH, baseline liver metastasis and CNS metastasis may be used as markers/influencing factors for predicting the efficacy of ICIs in SCLC patients. Non-Asian SCLC patients had better efficacy with ICIs in our results.

Epithelial-mesenchymal transition-related gene prognostic index and phenotyping clusters for hepatocellular carcinoma patients

Epithelial-mesenchymal transition (EMT) contributes to high tumor heterogeneity and the immunosuppressive environment of the HCC tumor microenvironment (TME). Here, we developed EMT-related genes phenotyping clusters and systematically evaluated their impact on HCC prognosis, the TME, and drug efficacy prediction. We identified HCC specific EMT-related genes using weighted gene co-expression network analysis (WGCNA). An EMT-related genes prognostic index (EMT-RGPI) capable of effectively predicting HCC prognosis was then constructed. Consensus clustering of 12 HCC specific EMT-related hub genes uncovered two molecular clusters C1 and C2. Cluster C2 preferentially associated with unfavorable prognosis, higher stemness index (mRNAsi) value, elevated immune checkpoint expression, and immune cell infiltration. The TGF-β signaling, EMT, glycolysis, Wnt β-catenin signaling, and angiogenesis were markedly enriched in cluster C2. Moreover, cluster C2 exhibited higher TP53 and RB1 mutation rates. The TME subtypes and tumor immune dysfunction and exclusion (TIDE) score showed that cluster C1 patients responded well to immune checkpoint inhibitors (ICIs). Half-maximal inhibitory concentration (IC50) revealed that cluster C2 patients were more sensitive to chemotherapeutic and antiangiogenic agents. These findings may guide risk stratification and precision therapy for HCC patients.

Systematic pan-cancer analysis showed that RAD51AP1 was associated with immune microenvironment, tumor stemness, and prognosis

Although RAD51 associated protein 1 (RAD51AP1) is crucial in genome stability maintenance, it also promotes cancer development with an unclear mechanism. In this study, we collected intact expression data of RAD51AP1 from the public database, and verified it was significantly over-expressed in 33 cancer types and correlated with poor prognosis in 13 cancer types, including glioma, adrenocortical carcinoma, lung adenocarcinoma. We further authenticated that RAD51AP1 is up-regulated in several typical cancer cell lines and promotes cancer cell proliferation in vitro. Moreover, we also demonstrated that RAD51AP1 was significantly positively related to cancer stemness score mRNAsi in 27 cancer types and broadly correlated to tumor-infiltrating immune cells in various cancers in a diverse manner. It was also negatively associated with immunophenoscore (IPS) and Estimation of STromal and Immune cells in MAlignant Tumours using Expression data (ESTIMATE) scores and positively correlated with mutant-allele tumor heterogeneity (MATH), tumor mutational burden (TMB), microsatellite instability (MSI), and PD-L1 expression in multiple cancers. The tumor stemness enhancing and tumor immune microenvironment affecting functions of RAD51AP1 might compose its carcinogenesis mechanism. Further investigations beyond the bioinformatics level should confirm these findings in each specific cancer.

A New Survival Score for Patients ≥65 Years Assigned to Radiotherapy of Bone Metastases

Survival scores are important for personalized treatment of bone metastases. Elderly patients are considered a separate group. Therefore, a specific score was developed for these patients. Elderly patients (≥65 years) irradiated for bone metastases were randomly assigned to the test (n = 174) or validation (n = 174) cohorts. Thirteen factors were retrospectively analyzed for survival. Factors showing significance (p < 0.05) or a trend (p < 0.06) in the multivariate analysis were used for the score. Based on 6-month survival rates, prognostic groups were formed. The score was compared to an existing tool developed in patients of any age. In the multivariate analysis, performance score, tumor type, and visceral metastases showed significance and gender was a trend. Three groups were designed (17, 18−25 and 27−28 points) with 6-month survival rates of 0%, 51%, and 100%. In the validation cohort, these rates were 9%, 55%, and 86%. Comparisons of prognostic groups between both cohorts did not reveal significant differences. In the test cohort, positive predictive values regarding death ≤6 and survival ≥6 months were 100% with the new score vs. 80% and 88% with the existing tool. The new score was more accurate demonstrating the importance of specific scores for elderly patients.

Characterization of the functional effects of ferredoxin 1 as a cuproptosis biomarker in cancer

Background: Cuproptosis is a recently discovered form of programmed cell death. Ferredoxin 1 (FDX1) is a key gene that mediates this process. However, the role of FDX1 in human tumors is not clear.

Methods: We comprehensively analyzed the differential expression and genetic alterations of FDX1 using multiomics data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) database. Subsequently, we explored the association between FDX1 and tumor parameters such as genomic instability, RNA methylation modifications, immune infiltration and pathway activity. In addition, we performed functional enrichment analysis and assessed the sensitivity potential of FDX1-related drugs. Finally, we experimentally verified the functional effects of FDX1.

Results: The analysis revealed differential expression of FDX1 in a variety of tumors. By analyzing the association of FDX1 expression with genomic instability, immune cell infiltration, signaling pathway etc. We explored the role of FDX1 in regulating cell activity. Also, we evaluated the function of FDX1 in biologic process and drug sensitivity. Our experimental results demonstrated that FDX1 exerts its antitumor effects through cuproptosis in liver hepatocellular carcinoma and non-small cell lung cancer cell lines.

Conclusion: Our study reveals the functional effects of FDX1 in tumors and deepens the understanding of the effects of FDX1. We validated the inhibitory effect of FDX1 in copper induced cell-death, confirming the role of FDX1 as a cuproptosis biomarker.

p53: From Fundamental Biology to Clinical Applications in Cancer

p53 tumour suppressor gene is our major barrier against neoplastic transformation. It is involved in many cellular functions, including cell cycle arrest, senescence, DNA repair, apoptosis, autophagy, cell metabolism, ferroptosis, immune system regulation, generation of reactive oxygen species, mitochondrial function, global regulation of gene expression, miRNAs, etc. Its crucial importance is denounced by the high percentage of amino acid sequence identity between very different species (Homo sapiens, Drosophila melanogaster, Rattus norvegicus, Danio rerio, Canis lupus familiaris, Gekko japonicus). Many of its activities allowed life on Earth (e.g., repair from radiation-induced DNA damage) and directly contribute to its tumour suppressor function. In this review, we provide paramount information on p53, from its discovery, which is an interesting paradigm of science evolution, to potential clinical applications in anti-cancer treatment. The description of the fundamental biology of p53 is enriched by specific information on the structure and function of the protein as well by tumour/host evolutionistic perspectives of its role.

Construction of a predictive model for immunotherapy efficacy in lung squamous cell carcinoma based on the degree of tumor-infiltrating immune cells and molecular typing

Background

To construct a predictive model of immunotherapy efficacy for patients with lung squamous cell carcinoma (LUSC) based on the degree of tumor-infiltrating immune cells (TIIC) in the tumor microenvironment (TME).

Methods

The data of 501 patients with LUSC in the TCGA database were used as a training set, and grouped using non-negative matrix factorization (NMF) based on the degree of TIIC assessed by single-sample gene set enrichment analysis (GSEA). Two data sets (GSE126044 and GSE135222) were used as validation sets. Genes screened for modeling by least absolute shrinkage and selection operator (LASSO) regression and used to construct a model based on immunophenotyping score (IPTS). RNA extraction and qPCR were performed to validate the prognostic value of IPTS in our independent LUSC cohort. The receiver operating characteristic (ROC) curve was constructed to determine the predictive value of the immune efficacy. Kaplan–Meier survival curve analysis was performed to evaluate the prognostic predictive ability. Correlation analysis and enrichment analysis were used to explore the potential mechanism of IPTS molecular typing involved in predicting the immunotherapy efficacy for patients with LUSC.

Results

The training set was divided into a low immune cell infiltration type (C1) and a high immune cell infiltration type (C2) by NMF typing, and the IPTS molecular typing based on the 17-gene model could replace the results of the NMF typing. The area under the ROC curve (AUC) was 0.82. In both validation sets, the IPTS of patients who responded to immunotherapy were significantly higher than those who did not respond to immunotherapy (P = 0.0032 and P = 0.0451), whereas the AUC was 0.95 (95% CI = 1.00–0.84) and 0.77 (95% CI = 0.58–0.96), respectively. In our independent cohort, we validated its ability to predict the response to cancer immunotherapy, for the AUC was 0.88 (95% CI = 1.00–0.66). GSEA suggested that the high IPTS group was mainly involved in immune-related signaling pathways.

Conclusions

IPTS molecular typing based on the degree of TIIC in the TME could well predict the efficacy of immunotherapy in patients with LUSC with a certain prognostic value.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03565-7.

Neoadjuvant chemoradiotherapy with camrelizumab in patients with locally advanced esophageal squamous cell carcinoma

Background

Neoadjuvant anti-programmed death receptor-1 (PD-1) blockade has been reported to improve the prognosis of locally advanced esophageal squamous cell carcinoma (ESCC). This study was aimed to evaluate the efficacy and safety of neoadjuvant camrelizumab plus chemoradiotherapy in locally advanced ESCC.

Methods

We retrospectively enrolled ESCC patients who received camrelizumab plus chemoradiotherapy as neoadjuvant therapy before surgery from May 2019 to September 2021.

Results

A total of 38 eligible patients were enrolled. The neoadjuvant treatment was well tolerated with no serious treatment-related adverse events. 36 (94.7%) patients achieved a R0 resection without hospital mortality or any other serious intraoperative complications. The objective response rate (ORR) was 63.2% and the disease control rate (DCR) was 100.0%. The major pathological response (MPR) was 50.0% and the complete pathological response (pCR) was 39.5%. With a median follow-up of 18.5 months, 6 (15.8%) patients had died. The overall survival (OS) and disease-free survival (DFS) at 12 months were 87.6% and 78.7%, respectively. Subgroup analysis demonstrated that patients who got MPR or pCR achieved improved survival, while PD-L1 expression did not reach statistically difference in predicting survival.

Conclusions

Neoadjuvant camrelizumab plus chemoradiotherapy is safe and efficacious in treating patients with locally advanced ESCC.

The Safety and Efficacy of Neoadjuvant Camrelizumab Plus Chemotherapy in Patients with Locally Advanced Esophageal Squamous Cell Carcinoma: A Retrospective Study

Background

Neoadjuvant anti-programmed death receptor-1 (PD-1) blockade has been explored in the treatment of locally advanced esophageal squamous cell carcinoma (ESCC). We conducted this study to assess the efficacy and safety of neoadjuvant camrelizumab plus chemotherapy in locally advanced ESCC.

Methods

We retrospectively enrolled ESCC patients who received surgery within 3 months of treatment with camrelizumab plus chemotherapy from June 2019 to January 2021.

Results

A total of 34 eligible patients were enrolled. The neoadjuvant treatment was well tolerated with no serious treatment-related adverse events. Thirty-two (94.1%) patients achieved a R0 resection, and 14 patients (41.2%) developed postoperative complications. The objective response rate (ORR) was 61.8% and the disease control rate (DCR) was 100.0%. The major pathological response (MPR), pathological complete response (pCR), and clinical to pathological downstaging rate were 50.0%, 35.3%, and 79.4%, respectively. With a median follow-up of 14.8 months, 30 (88.2%) patients who underwent surgical resection remain alive. The disease-free survival (DFS) and overall survival (OS) at 12 months were 86.4% and 92.8%, respectively.

Conclusion

Neoadjuvant camrelizumab plus chemotherapy is safe and efficacious in treating patients with locally advanced ESCC.