Predictive value of PD-L1 expression in response to immune checkpoint inhibitors for esophageal cancer treatment: A systematic review and meta-analysis

Synergistic Immunoregulation: harnessing CircRNAs and PiRNAs to Amplify PD-1/PD-L1 Inhibition Therapy

The utilization of PD-1/PD-L1 inhibitors marks a significant advancement in cancer therapy. However, the efficacy of monotherapy is still disappointing in a substantial subset of patients, necessitating the exploration of combinational strategies. Emerging from the promising results of the KEYNOTE-942 trial, RNA-based therapies, particularly circRNAs and piRNAs, have distinguished themselves as innovative sensitizers to immune checkpoint inhibitors (ICIs). These non-coding RNAs, notable for their stability and specificity, were once underrecognized but are now known for their crucial roles in regulating PD-L1 expression and bolstering anti-cancer immunity. Our manuscript offers a comprehensive analysis of selected circRNAs and piRNAs, elucidating their immunomodulatory effects and mechanisms, thus underscoring their potential as ICIs enhancers. In conjunction with the recent Nobel Prize-awarded advancements in mRNA vaccine technology, our review highlights the transformative implications of these findings for cancer treatment. We also discuss the prospects of circRNAs and piRNAs in future therapeutic applications and research. This study pioneers the synergistic application of circRNAs and piRNAs as novel sensitizers to augment PD-1/PD-L1 inhibition therapy, demonstrating their unique roles in regulating PD-L1 expression and modulating immune responses. Our findings offer a groundbreaking approach for enhancing the efficacy of cancer immunotherapy, opening new avenues for treatment strategies. This abstract aims to encapsulate the essence of our research and the burgeoning role of these non-coding RNAs in enhancing PD-1/PD-L1 inhibition therapy, encouraging further investigation into this promising field.

An updated review of immunotherapy in esophageal cancer: PD-L1 footprint

Esophageal cancer is considered one of the most significant challenges to public health worldwide. While various therapeutic options exist for esophageal cancer, including chemotherapy, radiotherapy, and surgery, several adverse effects of these medications have been reported. Therefore, a new generation of therapeutic lines should be applied to minimize complications. In this regard, immunotherapy is a novel approach that aims to kill tumor cells directly by targeting them. Specifically, monoclonal antibodies can target specific markers of esophageal cancer tumor cells, keeping other normal cells safe. Multiple monoclonal antibodies optimized for esophageal cancer, such as pembrolizumab, ramucirumab, trastuzumab, nivolumab, and ipilimumab, are available. On the other hand, esophageal cancer tumor cells express a specific inhibitory ligand and its receptor called programmed cell death, which can suppress T cell immune responses. This receptor provides an inhibitory signal, causing the highest expression of the PD-L1 ligand on tumor cells. The outcomes of this interaction lead to the suppression of the activation and function of T lymphocytes. Therefore, immunotherapy for esophageal cancer targeting the PD-1/PD-L1 pathway has shown a remarkable correlation with cancer care. This study presents a comprehensive review of the latest findings related to immunotherapy in esophageal cancer.

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

As a highly invasive malignancy, esophageal cancer (EC) is a global health issue, and was the eighth most prevalent cancer and the sixth leading cause of cancer-related death worldwide in 2020. Due to its highly immunogenic nature, emer-ging immunotherapy approaches, such as immune checkpoint blockade, have demonstrated promising efficacy in treating EC; however, certain limitations and challenges still exist. In addition, tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment (TIME); thus, understanding the TIME is urgent and crucial, especially given the im-portance of an immunosuppressive microenvironment in tumor progression. The aim of this review was to better elucidate the mechanisms of the suppressive TIME, including cell infiltration, immune cell subsets, cytokines and signaling pathways in the tumor microenvironment of EC patients, as well as the downregulated expression of major histocompatibility complex molecules in tumor cells, to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of immunotherapies. Therefore, personalized treatments could be developed to maximize the advantages of immunotherapy.

The predictive value of PD-L1 expression in response to anti-PD-1/PD-L1 therapy for biliary tract cancer: a systematic review and meta-analysis

Background

Recently, anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy offers promising results for advanced biliary tract cancer (BTC). However, patients show highly heterogeneous responses to treatment, and predictive biomarkers are lacking. We performed a systematic review and meta-analysis to assess the potential of PD-L1 expression as a biomarker for treatment response and survival in patients with BTC undergoing anti-PD-1/PD-L1 therapy.

Methods

We conducted a comprehensive systematic literature search through June 2023, utilizing the PubMed, EMBASE, and Cochrane Library databases. The outcomes of interest included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) according to PD-L1 expression. Subgroup analyses and meta-regression were performed to identify possible sources of heterogeneity.

Results

A total of 30 studies was included in the final analysis. Pooled analysis showed no significant differences in ORR (odds ratio [OR], 1.56; 95% confidence intervals [CIs], 0.94-2.56) and DCR (OR, 1.84; 95% CIs, 0.88-3.82) between PD-L1 (+) and PD-L1 (-) patients. In contrast, survival analysis showed improved PFS (hazard ratio [HR], 0.54, 95% CIs, 0.41-0.71) and OS (HR, 0.58; 95% CI, 0.47-0.72) among PD-L1 (+) patients compared to PD-L1 (-) patients. Sensitivity analysis excluding retrospective studies showed no significant differences with the primary results. Furthermore, meta-regression demonstrated that drug target (PD-1 vs. PD-L1), presence of additional intervention (monotherapy vs. combination therapy), and PD-L1 cut-off level (1% vs. ≥5%) significantly affected the predictive value of PD-L1 expression.

Conclusion

PD-L1 expression might be a helpful biomarker for predicting PFS and OS in patients with BTC undergoing anti-PD-1/PD-L1 therapy. The predictive value of PD-L1 expression can be significantly influenced by diagnostic or treatment variables.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023434114.

Toripalimab, a therapeutic monoclonal anti-PD-1 antibody with high binding affinity to PD-1 and enhanced potency to activate human T cells

Over the past decade, US Food and Drug Administration (FDA)-approved immune checkpoint inhibitors that target programmed death-1 (PD-1) have demonstrated significant clinical benefit particularly in patients with PD-L1 expressing tumors. Toripalimab is a humanized anti-PD-1 antibody, approved by FDA for first-line treatment of nasopharyngeal carcinoma in combination with chemotherapy. In a post hoc analysis of phase 3 studies, toripalimab in combination with chemotherapy improved overall survival irrespective of PD-L1 status in nasopharyngeal carcinoma (JUPITER-02), advanced non-small cell lung cancer (CHOICE-01) and advanced esophageal squamous cell carcinoma (JUPITER-06). On further characterization, we determined that toripalimab is molecularly and functionally differentiated from pembrolizumab, an anti-PD-1 mAb approved previously for treating a wide spectrum of tumors. Toripalimab, which binds the FG loop of PD-1, has 12-fold higher binding affinity to PD-1 than pembrolizumab and promotes significantly more Th1- and myeloid-derived inflammatory cytokine responses in healthy human PBMCs in vitro. In an ex vivo system employing dissociated tumor cells from treatment naïve non-small cell lung cancer patients, toripalimab induced several unique genes in IFN-γ and immune cell pathways, showed different kinetics of activation and significantly enhanced IFN-γ signature. Additionally, binding of toripalimab to PD-1 induced lower levels of SHP1 and SHP2 recruitment, the negative regulators of T cell activation, in Jurkat T cells ectopically expressing PD-1. Taken together, these data demonstrate that toripalimab is a potent anti-PD-1 antibody with high affinity PD-1 binding, strong functional attributes and demonstrated clinical activity that encourage its continued clinical investigation in several types of cancer.

Immune checkpoint inhibitors in gastrointestinal malignancies: an Umbrella review

In the Modern era, immune checkpoint inhibitors (ICIs) have been the cornerstone of success in the treatment of several malignancies. Despite remarkable therapeutic advances, complex matrix together with significant molecular and immunological differences have led to conflicting outcomes of ICI therapy in gastrointestinal (GI) cancers. As far we are aware, to date, there has been no study to confirm the robustness of existing data, and this study is the first umbrella review to provide a more comprehensive picture about ICIs' efficacy and safety in GI malignancies. Systematic search on PubMed, Scopus, Web of Science, EMBASE, and Cochrane library identified 14 meta-analyses. The pooled analysis revealed that ICIs application, especially programmed death-1 (PD-1) inhibitors such as Camrelizumab and Sintilimab, could partially improve response rates in patients with GI cancers compared to conventional therapies. However, different GI cancer types did not experience the same efficacy; it seems that hepatocellular carcinoma (HCC) and esophageal cancer (EC) patients are likely better candidates for ICI therapy than GC and CRC patients. Furthermore, application of ICIs in a combined-modal strategy are perceived opportunity in GI cancers. We also assessed the correlation of PD-L1 expression as well as microsatellite status with the extent of the response to ICIs; overall, high expression of PD-L1 in GI cancers is associated with better response to ICIs, however, additional studies are required to precisely elaborate ICI responses with respect to microsatellite status in different GI tumors. Despite encouraging ICI efficacy in some GI cancers, a greater number of serious and fatal adverse events have been observed; further highlighting the fact that ICI therapy in GI cancers is not without cost, and further studies are required to utmost optimization of this approach in GI cancers.

Efficacy and Safety of First-line Therapies for Advanced Unresectable Oesophageal Squamous Cell Cancer: a Systematic Review and Network Meta-analysis

AIM

To compare the clinical efficacy and safety of first-line treatments for advanced unresectable oesophageal squamous cell cancer.

MATERIALS AND METHODS

A systematic review and network meta-analysis was carried out by retrieving and retaining relevant literature from databases. The studies were randomised controlled trials comparing first-line treatments for advanced unresectable oesophageal squamous cell cancer. A Bayesian network meta-analysis was used to assess clinical outcomes.

RESULTS

Nine studies including 4499 patients receiving first-line treatments were analysed. For all populations, toripalimab plus chemotherapy tended to provide the best overall survival (hazard ratio 0.58, 95% confidence intervals 0.43-0.78) and sintilimab plus chemotherapy provided the best progression-free survival (0.56, 0.46-0.68). Nivolumab plus chemotherapy presented the best objective response rate (odds ratio 2.45, 1.78-3.42) and camrelizumab plus chemotherapy (0.47, 0.29-0.74) appeared to be the safest. Sintilimab plus chemotherapy (0.55, 0.40-0.75) and nivolumab (0.54, 0.37-0.80) plus chemotherapy had the best overall survival in programmed death ligand 1 (PD-L1) tumour proportion score <1% and ≥1% subgroups. Toripalimab plus chemotherapy (0.61, 0.40-0.93) and pembrolizumab (0.57, 0.43-0.75) were the best in overall survival in combined positive score <10 and ≥10 subgroups, respectively. Toripalimab plus chemotherapy showed the best overall survival in the Asian group; pembrolizumab presented better overall survival in the Asian population than the non-Asian group.

CONCLUSION

Most immunotherapy combined with chemotherapy showed superior clinical benefits and sintilimab plus chemotherapy, toripalimab plus chemotherapy and tislelizumab plus chemotherapy had better comprehensive clinical efficacy. PD-L1 expression detection and ethnicity differences are still of great significance and most suitable regimens varied from each subgroup.

Coptisine, the Characteristic Constituent from Coptis chinensis, Exhibits Significant Therapeutic Potential in Treating Cancers, Metabolic and Inflammatory Diseases

Naturally derived alkaloids belong to a class of quite significant organic compounds. Coptisine, a benzyl tetrahydroisoquinoline alkaloid, is one of the major bioactive constituents in Coptis chinensis Franch., which is a famous traditional Chinese medicine. C. chinensis possesses many kinds of functions, including the ability to eliminate heat, expel dampness, purge fire, and remove noxious substances. In Asian countries, C. chinensis is traditionally employed to treat carbuncle and furuncle, diabetes, jaundice, stomach and intestinal disorders, red eyes, toothache, and skin disorders. Up to now, there has been plenty of research of coptisine with respect to its pharmacology. Nevertheless, a comprehensive review of coptisine-associated research is urgently needed. This paper was designed to summarize in detail the progress in the research of the pharmacology, pharmacokinetics, safety, and formulation of coptisine. The related studies included in this paper were retrieved from the following academic databases: The Web of Science, PubMed, Google scholar, Elsevier, and CNKI. The cutoff date was January 2023. Coptisine manifests various pharmacological actions, including anticancer, antimetabolic disease, anti-inflammatory disease, and antigastrointestinal disease effects, among others. Based on its pharmacokinetics, the primary metabolic site of coptisine is the liver. Coptisine is poorly absorbed in the gastrointestinal system, and most of it is expelled in the form of its prototype through feces. Regarding safety, coptisine displayed potential hepatotoxicity. Some novel formulations, including the [Formula: see text]-cyclodextrin-based inclusion complex and nanocarriers, could effectively enhance the bioavailability of coptisine. The traditional use of C. chinensis is closely connected with the pharmacological actions of coptisine. Although there are some disadvantages, including poor solubility, low bioavailability, and possible hepatotoxicity, coptisine is still a prospective naturally derived drug candidate, especially in the treatment of tumors as well as metabolic and inflammatory diseases. Further investigation of coptisine is necessary to facilitate the application of coptisine-based drugs in clinical practice.

Nivolumab adjuvant therapy for esophageal cancer: a review based on subgroup analysis of CheckMate 577 trial

Esophageal cancer is the sixth most common cancer worldwide. Approximately 50% of patients have locally advanced disease. The CROSS and NEOCRTEC5010 trials have demonstrated that neoadjuvant chemoradiotherapy followed by surgery is the standard treatment for patients with resectable disease. However, a pathological complete response is frequently not achieved, and most patients have a poor prognosis. The CheckMate 577 trial demonstrates that nivolumab adjuvant therapy improves disease-free survival in patents without a pathological complete response. However, there are still numerous clinical questions of concern that remain controversial based on the results of the subgroup analysis. In this review, we aim to offer constructive suggestions addressing the clinical concerns raised in the CheckMate 577 trial.

Predictive value of PD-L1 expression in response to immune checkpoint inhibitors for gastric cancer treatment: a systematic review and meta-analysis

BACKGROUND

Which patients may benefit more from immune checkpoint inhibitors (ICIs) is still an important question. The present study aimed to investigate the role of the PD-L1 molecule in predicting the effectiveness of PD-1/PD-L1 inhibitors in gastric cancer patients.

METHOD

We searched PubMed, Scopus, Web of Science, and EMBASE databases as of 25 March 202225 March 2022.

RESULTS

Ten articles were included. When we used the TPS method for PD-L1 expression, none of the patients in tumor proportion score (TPS)≥1% and TPS < 1% groups took advantage of ICI therapy in terms of OS and PFS. However, gastric cancer patients with combined-positive score (CPS)≥1, CPS ≥ 5, and CPS ≥ 10 tumors represented superior OS for ICIs over the control agents, while their counterparts (i.e. patients with CPS < 1, CPS < 5, and CPS < 10 tumors) did not. In the subgroup analysis when patients with CPS ≥ 1 were selected, Nivolumab improved the OS and PFS remarkably by 26% and 25% when compared with control agents, respectively. However, Pembrolizumab significantly increased the rate of disease progression by 47% relative to the control medications.

CONCLUSION

Among patients suffering from gastric cancer, considering PD-L1 CPS thresholds seems to be a more reliable predictive factor than TPS threshold for lower rate of mortality when PD-1/PD-L1 inhibitors are administered.