Margetuximab plus pembrolizumab in patients with previously treated, HER2-positive gastro-oesophageal adenocarcinoma (CP-MGAH22-05): a single-arm, phase 1b-2 trial

Discussion on the mechanism of HER2 resistance in esophagogastric junction and gastric cancer in the era of immunotherapy

Human epidermal growth factor receptor 2 (HER2) is a critical biomarker and therapeutic target in gastric/gastroesophageal junction (G/GEJ) cancers, despite the initial success of HER2-targeted therapies, such as trastuzumab, resistance to these drugs has emerged as a major impediment to effective long-term treatment. This review examines the mechanisms of drug resistance in HER2-positive G/GEJ cancer, the primary mechanisms of resistance explored include alterations in the HER2 receptor itself, such as mutations and changes in expression levels, as well as downstream signaling pathways, and interactions with the tumor microenvironment (TME). Furthermore, the review discusses the Novel therapeutic approaches, including the use of antibody-drug conjugates (ADCs) and combination therapies are assessed for their potential to enhance outcomes. By integrating recent research findings and clinical trials, this review aims to provide oncologists and researchers with insights into developing more effective treatments for patients with drug-resistant HER2-positive G/GEJ cancer.

Study of immunosenescence in the occurrence and immunotherapy of gastrointestinal malignancies

In human beings heterogenous, pervasive and lethal malignancies of different parts of the gastrointestinal (GI) tract viz., tumours of the oesophagus, stomach, small intestine, colon, and rectum, represent gastrointestinal malignancies. Primary treatment modality for gastric cancer includes chemotherapy, surgical interventions, radiotherapy, monoclonal antibodies and inhibitors of angiogenesis. However, there is a need to improve upon the existing treatment modality due to associated adverse events and the development of resistance towards treatment. Additionally, age has been found to contribute to increasing the incidence of tumours due to immunosenescence-associated immunosuppression. Immunosenescence is the natural process of ageing, wherein immune cells as well as organs begin to deteriorate resulting in a dysfunctional or malfunctioning immune system. Accretion of senescent cells in immunosenescence results in the creation of a persistent inflammatory environment or inflammaging, marked with elevated expression of pro-inflammatory and immunosuppressive cytokines and chemokines. Perturbation in the T-cell pools and persistent stimulation by the antigens facilitate premature senility of the immune cells, and senile immune cells exacerbate inflammaging conditions and the inefficiency of the immune system to identify the tumour antigen. Collectively, these conditions contribute positively towards tumour generation, growth and eventually proliferation. Thus, activating the immune cells to distinguish the tumour cells from normal cells and invade them seems to be a logical strategy for the treatment of cancer. Consequently, various approaches to immunotherapy, viz., programmed death ligand-1 (PD-1) inhibitors, Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors etc are being extensively evaluated for their efficiency in gastric cancer. In fact, PD-1 inhibitors have been sanctioned as late late-line therapy modality for gastric cancer. The present review will focus on deciphering the link between the immune system and gastric cancer, and the alterations in the immune system that incur during the development of gastrointestinal malignancies. Also, the mechanism of evasion by tumour cells and immune checkpoints involved along with different approaches of immunotherapy being evaluated in different clinical trials will be discussed.

Reshaping the immune microenvironment and reversing immunosenescence by natural products: Prospects for immunotherapy in gastric cancer

Gastric cancer (GC) represents a global health-care challenge. Recent progress in immunotherapy has elicited attracted considerable attention as a viable treatment option through modulating the host immune system and unleashing pre-existing immunity, which has profoundly revolutionized oncology, especially GC. Nonetheless, low clinical response and intrinsic and acquired resistance remain persistently challenging. The microenvironment of GC comprising multifarious stromal cell types has remarkable immunosuppressive elements that may impact the efficacy of immunotherapy. Immunosenescence is increasingly regarded as a factor that contributes to cancer development, remodels the tumor microenvironment and affects the efficacy of immunotherapy. Natural products are at the forefront of traditional medicine. Senotherapeutics is a class of drugs and natural products capable of delaying, preventing, or reversing the senescence process (i.e., senolytics) or suppressing senescence-associated secretory phenotype (i.e., senomorphics). Emerging evidence supports that natural products can improve the efficacy of existing immunotherapy and expand their indications in GC mainly based upon remodeling the immunosuppressive microenvironment and reversing immunosenescence. The review provides an integrated review of previously reported and ongoing clinical trials with immunotherapeutic regimens in GC and discusses current challenges. Next, we focus on natural compounds that exert anti-GC functions and possess immunomodulatory properties. More attention is paid to the potential of these natural compounds in modulating the immune microenvironment and immunosenescence. Lastly, we discuss the nanomedicine that can overcome the deficiencies of natural products. Altogether, our review suggests the enormous potential of natural compounds in GC immunotherapy, and provides an important direction for future research.

Assessment of Circulating Tumor DNA Burden in Patients With Metastatic Gastric Cancer Using Real-World Data

PURPOSE

Circulating tumor DNA (ctDNA) has emerged as a promising biomarker with prognostic and potentially predictive value for several tumor types, including gastric cancer (GC). This study uses real-world data (RWD) to investigate the association of pretreatment ctDNA burden with clinical outcomes among patients with first-line (1L)-treated metastatic gastric cancer (mGC) in the United States.

METHODS

Patients were identified from the GuardantINFORM real-world clinical-genomic database. Adult patients with mGC who underwent testing with the Guardant360 assay from June 2014 to March 2022 and within 60 days before 1L treatment were included. The median of the maximum variant allele fraction (MVAF) was used to classify patients into high or low ctDNA burden groups, with undetectable ctDNA burden included in the low group. Associations with real-world outcome variables derived from claims, including time to treatment discontinuation (rwTTD), time to next treatment (rwTTNT), and overall survival (rwOS), were assessed using log-rank tests and multivariable Cox models.

RESULTS

A cohort of 824 patients with mGC was identified. Median MVAF was 2.9%, with 91% having detectable ctDNA. Among patients receiving chemo-based treatment (n = 537), rwTTDs were similar in low and high ctDNA burden groups, while those with high ctDNA burden showed significantly shorter rwTTNT and rwOS (median rwTTNT = 4.8 months v 7.4 months, P < .001; median rwOS = 13.2 months v 19.1 months, P < .001). Multivariable Cox analyses showed similar results. ctDNA burden in immunotherapy (n = 100) and trastuzumab-based (n = 99) treatment groups did not have significant associations with outcomes.

CONCLUSION

We used RWD to demonstrate that high pretreatment ctDNA burden was associated with worse clinical outcomes in a mGC population receiving 1L chemotherapy-based treatments. Our analysis suggests ctDNA burden could be used as a prognostic biomarker for mGC.

Combining immune checkpoint inhibitors with standard treatment regimens in advanced human epidermal growth factor receptor-2 positive gastric cancer patients

BACKGROUND

Gastric cancer is one of the most common malignant tumors worldwide, with its incidence and mortality rates ranking among the highest in gastrointestinal cancers. The overexpression or gene amplification of human epidermal growth factor receptor 2 (HER-2) occurs in approximately 15%-20% of gastric cancers and serves as a critical molecular target influencing prognosis and treatment outcomes. For patients with HER-2-positive gastric cancer, trastuzumab combined with platinum-based chemotherapy has been established as the standard first-line treatment. However, despite the demonstrated clinical benefits in prolonging survival, the overall efficacy remains limited. In recent years, with the successful application of immune checkpoint inhibitors (ICIs) in various malignant tumors, combining ICIs with existing standard treatment regimens has emerged as a promising approach to enhance the therapeutic efficacy of HER-2-positive gastric cancer. Nevertheless, the efficacy and prognostic factors of ICIs combined with trastuzumab and chemotherapy in HER-2-positive gastric cancer remain unclear.

AIM

To analyze the efficacy of ICIs combined with standard treatment regimens and the prognostic factors in patients with advanced HER-2-positive gastric cancer.

METHODS

Clinical data from 104 patients with advanced HER-2-positive gastric cancer who were treated at our hospital between March 2021 and May 2023 were retrospectively analyzed. Patients were divided into a control group (n = 54, treated with trastuzumab combined with platinum-based chemotherapy as the standard regimen) and an observation group (n = 50, treated with ICIs in addition to the standard regimen). The therapeutic efficacy, survival outcomes, and adverse reactions were compared between the two groups. Univariate and Cox multivariate analyses were performed to identify factors influencing patient prognosis.

RESULTS

With a median follow-up time of 14.6 months, there were no significant differences between the two groups in terms of objective response rate or disease control rate (P > 0.05). The median progression-free survival (mPFS) and mPFS for patients with immunohistochemistry 3 + in the observation group were significantly higher than those in the control group (P < 0.05). Among patients in the observation group, those with positive programmed death-ligand 1 (PD-L1) expression had a significantly higher mPFS than those with negative PD-L1 expression (P < 0.05). Regarding adverse events, significant differences were observed between the two groups in hypothyroidism and neutropenia (P < 0.05). Cox multivariate analysis showed that Eastern Cooperative Oncology Group (ECOG) performance status, peritoneal metastasis, positive programmed death-1 expression, and treatment regimen were independent factors influencing PFS (hazard ratio > 1, P < 0.05).

CONCLUSION

ICIs combined with standard treatment regimens for patients with advanced HER-2-positive gastric cancer demonstrate favorable clinical efficacy, significantly prolonging PFS with manageable safety. ECOG performance status, peritoneal metastasis, positive PD-L1 expression, and treatment regimen are independent factors influencing PFS, warranting increased clinical attention to patients exhibiting these factors.

Applications and challenges of immunotherapy in the management of gastric adenocarcinoma: current status and future perspectives

Gastric adenocarcinoma (GAC) remains a significant global public health challenge, characterized by high incidence and mortality rates. Progress in tumor immunology has introduced immune checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathways, demonstrating substantial potential in GAC therapy. Clinical research indicates that ICIs, particularly when combined with chemotherapy or targeted therapies, significantly enhance treatment efficacy in advanced GAC and specific molecular subtypes, including microsatellite instability-high (MSI-H) and human epidermal growth factor receptor 2 (HER2)-positive patients. However, immunotherapy is also associated with a range of immune-related adverse events (irAEs), necessitating effective management strategies to ensure treatment safety and maintain patients' quality of life. Future studies should focus on identifying new therapeutic targets, optimizing patient selection, and developing personalized treatment approaches to further improve the efficacy and safety of immunotherapy in GAC.

Efficacy and safety of KN026, a bispecific anti-HER2 antibody, in combination with KN046, an anti-CTLA4/PD-L1 antibody, in patients with advanced HER2-positive nonbreast cancer: a combined analysis of a phase Ib and a phase II study

To evaluate the efficacy and safety of KN026, a novel bispecific HER2 (ECD2 and ECD4) antibody, plus KN046, a PD-L1, and CTLA4 bispecific antibody, in patients with advanced HER2-positive solid tumors. We conducted two sequentially designed phase Ib and II studies with similar target populations and evaluation schedules. The primary endpoints included safety, maximum tolerated dose (MTD), the recommended phase II dose (RP2D) for the phase Ib study, and the objective response rate (ORR) and duration of response (DoR) for the phase II study. Hereby, we solely report the results from 113 nonbreast cancer patients. In phase Ib, MTD was not reached. Dose 3 was confirmed to be acceptable for the phase II study. An objective response has been exclusively observed in HER2-positive patients. Any grade treatment-related adverse events (TRAEs) were reported in 108 (95.6%) patients. The most common TRAEs were infusion reactions (38.9%), anemia (37.2%), elevated AST (31.0%), and diarrhea (30.1%). Among the 108 patients evaluated for efficacy, the overall ORR was 55.6% (95%CI, 45.7%, 65.1%). In the HER2-positive GC subgroup, 38 patients received this regimen as the 1st-line treatment and 30 patients achieved an objective response, with an ORR of 78.9% (95%CI, 62.7%, 90.4%). Among 27 pretreated patients, the ORR was 44.4% (95%CI, 25.5%, 64.7%). In the other HER2-positive solid tumor subgroup (n = 34), the ORR was 52.9% (95%CI 35.1%,70.2%). Thus, KN026 plus KN04 exhibits promising efficacy and acceptable safety profiles in HER2-positive nonbreast cancer, as does the 1st-line treatment for GC.

HER2-positive gastric cancer: from targeted therapy to CAR-T cell therapy

Gastric cancer (GC) ranks as the fifth most prevalent cancer on a global scale, with HER2-positive GC representing a distinct subtype that exhibits more intricate biological characteristics. Conventional chemotherapy typically exhibits restricted efficacy in the management of HER2-positive GC. In light of the incessant advancement in molecular targeted therapies, targeting HER2 has emerged as a promising therapeutic approach for this subtype. The advent of antibody-drug conjugates (ADCs) and chimeric antigen receptor T-cell therapy (CAR-T) has furnished novel treatment alternatives for HER2-positive GC. Nevertheless, owing to the pronounced heterogeneity of GC and the complex tumor microenvironment, drug resistance frequently emerges, thereby substantially influencing the effectiveness of HER2-targeted therapy. This article comprehensively summarizes and deliberates upon the strategies of HER2-targeted therapy as well as the underlying resistance mechanisms.

Bioinformatic analysis indicated that LINC01150 might be a novel neutrophil extracellular traps-related biomarker of gastric cancer

Gastric cancer (GC) is a highly aggressive malignancy associated with poor prognosis, particularly in its advanced stages. Neutrophil extracellular traps (NETs) have been implicated in cancer progression and immune therapy responses; however, the role of NETs-related long non-coding RNAs (lncRNAs) in GC remains poorly understood. This study used data from the Cancer Genome Atlas (TCGA) and previous research to identify NETs-related lncRNAs in GC. A prognostic signature comprising four NETs-related lncRNAs (NlncSig) was developed and validated, serving as a predictor for patient survival and response to immunotherapy. The NlncSig was correlated with poorer outcomes in high-risk patients and demonstrated that those with lower risk scores exhibited more favorable responses to immunotherapy. In vitro experiments confirmed that LINC01150 enhances GC cell proliferation, migration, and invasion. This robust NlncSig provides a reliable tool for predicting survival and immune characteristics in GC, with the potential to guide personalized therapeutic approaches and improve patient care.

Optimal early endpoint for second-line or subsequent immune checkpoint inhibitors in previously treated advanced solid cancers: a systematic review

BACKGROUND

The administration of second-line or subsequent immune checkpoint inhibitors (ICIs) in previously treated patients with advanced solid cancers has been clinically investigated. However, previous clinical trials lacked an appropriate primary endpoint for efficacy assessment. This systematic review aimed to explore the most optimal early efficacy endpoint for such trials.

METHODS

Phase 2 or 3 clinical trials involving patients with advanced solid cancers with disease progression following standard first-line therapy receiving second-line or subsequent ICI administration, with adequate survival outcome data, were included from PubMed, Embase, Web of Science, and Cochrane Library databases before February 2023. Quality assessment was conducted using the Cochrane tool and Newcastle-Ottawa Quality Assessment Scale for Cohort Studies for randomized controlled trials (RCTs) and non-randomized trials, respectively. Objective response rate (ORR) and progression-free survival (PFS) at 3, 6, and 9 months were investigated as potential early efficacy endpoint candidates for 12-month overall survival (OS), with a strong correlation defined as Pearson's correlation coefficient r ≥ 0.8.

RESULTS

A total of 64 RCTs comprising 22,725 patients and 106 non-randomized prospective trials involving 10,608 participants were eligible for modeling and external validation, respectively. RCTs examined 15 different cancer types, predominantly non-small-cell lung cancer (NSCLC) (17, 28%), melanoma (9, 14%), and esophageal squamous cell carcinoma (5, 8%). The median sample size of RCTs was 124 patients, and the median follow-up time was 3.2-57.7 months. The ORR (r = 0.38; 95% confidence interval [CI], 0.18-0.54) and PFS (r = 0.42; 95% CI, 0.14-0.64) exhibited weak trial-level correlations with OS. Within ICI treatment arms, the r values of ORR and 3-, 6-, and 9-month PFS with 12-month OS were 0.61 (95% CI, 0.37-0.79), 0.78 (95% CI, 0.62-0.88), 0.84 (95% CI, 0.77-0.90), and 0.86 (95% CI, 0.79-0.90), respectively. External validation of 6-month PFS indicated an acceptable discrepancy between actual and predicted 12-month OS.

CONCLUSIONS

In non-randomized phase 2 trials on second-line or subsequent ICI therapy in patients with advanced solid cancers, 6-month PFS could serve as an early efficacy endpoint. However, early efficacy endpoints are not recommended in RCTs to replace OS.

A literature review of recent advances in gastric cancer treatment: exploring the cross-talk between targeted therapies

BACKGROUND

Gastric cancer (GC) ranks fourth in global mortality rates and fifth in prevalence, making it one of the most common cancers worldwide. Recent clinical studies have highlighted the potential of immunotherapies as a promising approach to treating GC. This study aims to shed light on the most impactful therapeutic strategies in the context of GC immunotherapy, highlighting both established and emerging approaches.

MAIN BODY

This review examines over 160 clinical studies conducted globally, focusing on the effectiveness of various immunotherapy modalities, including cancer vaccines, adoptive cell therapy, immune checkpoint inhibitors (ICIs), and monoclonal antibodies (mAbs). A comprehensive search of peer-reviewed literature was performed using databases such as Web of Science, PubMed, and Scopus. The selection criteria included peer-reviewed articles published primarily within the last 10 years, with a focus on studies that provided insights into targeted therapies and their mechanisms of action, clinical efficacy, and safety profiles. The findings indicate that these immunotherapy strategies can enhance treatment outcomes for GC, aligning with current treatment guidelines. ICIs like pembrolizumab and nivolumab have shown significant survival benefits in specific GC subgroups. Cancer vaccines and CAR-T cell therapies demonstrate potential, while mAbs targeting HER2 and VEGFR pathways enhance outcomes in combination regimens. We discuss the latest advancements and challenges in targeted therapy and immunotherapy for GC. Given the evolving nature of this field, this research emphasizes significant evidence-based therapies and those currently under evaluation rather than providing an exhaustive overview. Challenges include resistance mechanisms, immunosuppressive tumor environments, and inconsistent results from combination therapies. Biomarker-driven approaches and further research into emerging modalities like CAR-T cells and cancer vaccines are critical for optimizing treatments.

CONCLUSIONS

Immunotherapy is reshaping GC management by improving survival and quality of life. Ongoing research and clinical evaluations are crucial for refining personalized and effective therapies.

A Phase I Trial of Trebananib, an Angiopoietin 1 and 2 Neutralizing Peptibody, Combined with Pembrolizumab in Patients with Advanced Ovarian and Colorectal Cancer

Ovarian cancers and microsatellite stable (MSS) colorectal cancers are insensitive to anti-programmed cell death 1 (PD-1) immunotherapy, and new immunotherapeutic approaches are needed. Preclinical data suggest a relationship between immunotherapy resistance and elevated angiopoietin 2 levels. We performed a phase I dose escalation study of pembrolizumab and the angiopoietin 1/2 inhibitor trebananib (NCT03239145). This multicenter trial enrolled patients with metastatic ovarian cancer or MSS colorectal cancer. Trebananib was administered intravenously weekly for 12 weeks with 200 mg intravenous pembrolizumab every 3 weeks. The toxicity profile of this combination was manageable, and the protocol-defined highest dose level (trebananib 30 mg/kg weekly plus pembrolizumab 200 mg every 3 weeks) was declared the maximum tolerated dose. The objective response rate for all patients was 7.3% (90% confidence interval, 2.5%-15.9%). Three patients with MSS colorectal cancer had durable responses for ≥3 years. One responding patient's colorectal cancer harbored a POLE mutation. The other two responding patients had left-sided colorectal cancers, with no baseline liver metastases, and genomic analysis revealed that they both had KRAS wild-type, ERBB2-amplified tumors. After development of acquired resistance, biopsy of one patient's KRAS wild-type ERBB2-amplified tumor showed a substantial decline in tumor-associated T cells and an increase in immunosuppressive intratumoral macrophages. Future studies are needed to carefully assess whether clinicogenomic features, such as lack of liver metastases, ERBB2 amplification, and left-sided tumors, can predict increased sensitivity to PD-1 immunotherapy combinations.

Human Epidermal Growth Factor Receptor 2 Positive Advanced Gastric or Esophagogastric Adenocarcinoma: Reflecting on the Past to Gain a New Insights

PURPOSE OF REVIEW

Human epidermal growth factor receptor 2 (HER2) is a critical target in advanced gastric cancer (AGC). This review highlights the current treatment landscape, lessons learned from past clinical trials, and prospects for future treatment strategies for HER2-positive AGC.

RECENT FINDINGS

Trastuzumab had been the standard treatment for HER2-positive AGC for a decade, and subsequently, trastuzumab deruxtecan, an antibody-drug conjugate (ADC), emerged with an impressive response. Recently, the addition of pembrolizumab to first-line chemotherapy plus trastuzumab has become a novel standard treatment. Past clinical trials of HER2-targeted therapies, which succeeded in HER2-positive breast cancer but failed in AGC, have deepened our understanding of resistance mechanisms. Based on these results, several clinical trials of novel HER2-targeted therapies, including immunologic approaches such as CAR-T cells and vaccines, are currently ongoing. Circulating tumor DNA is also expected to be a tool for real-time biomarker analysis. Additionally, ADCs with a bystander effect have the potential to expand the scope of HER2-targeted therapies to HER2-expressing, including HER2-low AGC. Learning from past trials, further development of novel HER2-targeted therapies is underway, expanding their scope to HER2-expressing AGC. Meanwhile, selecting optimal treatment is a challenging issue in cases with HER2-low AGC overlapping with other biomarkers like CLDN18.2.

Progress on angiogenic and antiangiogenic agents in the tumor microenvironment

The development of tumors and their metastasis relies heavily on the process of angiogenesis. When the volume of a tumor expands, the resulting internal hypoxic conditions trigger the body to enhance the production of various angiogenic factors. These include vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), and transforming growth factor-α (TGF-α), all of which work together to stimulate the activation of endothelial cells and catalyze angiogenesis. Antiangiogenic therapy (AAT) aims to normalize tumor blood vessels by inhibiting these angiogenic signals. In this review, we will explore the molecular mechanisms of angiogenesis within the tumor microenvironment, discuss traditional antiangiogenic drugs along with their limitations, examine new antiangiogenic drugs and the advantages of combination therapy, and consider future research directions in the field of antiangiogenic drugs. This comprehensive overview aims to provide insights that may aid in the development of more effective anti-tumor treatments.

Efficacy of sintilimab combined with neoadjuvant chemotherapy and trastuzumab in conversional treatment of locally advanced HER2-positive gastric cancer: case analysis and literature review

BACKGROUND

Regional lymph nodes that are fixed and fused into clusters or those exhibiting metastases outside the regional lymph nodes are generally classified as stage IV (M1) or unresectable. Patients with such nodes almost always need pre-operative treatment so that they can undergo surgical resection. Combining immunotherapy with trastuzumab and chemotherapy significantly improved the prognosis of HER-2 positive gastric/gastroesophageal junction (G/GEJ) cancer. However, very few reports are available on the role of immunotherapy in converting patients with unresectable cancer to resectable cancer.

METHODS

In this study, we report on four patients with GC who were preoperatively treated with a combination of sintilimab, trastuzumab, and chemotherapy at Hubei Cancer Hospital, China, from January 2022 to October 2023. Both preoperative and postoperative clinical and pathological characteristics of each patient were analyzed. The preoperative tumor stage was cT4N3M1.

RESULTS

Postoperative pathological results showed that two patients achieved pathological complete remission (pCR), while the pathological stage in the other two patients decreased to ypT1N0M0 and ypT2N0M0. None of them had nerve or vascular invasion. None of the patients had recurrences or metastases until the last follow-up (October 2024) after primary surgery. The present case report suggests that a combination of immunotherapy comprising trastuzumab and chemotherapy can improve the efficiency of conversion therapy for patients with HER-2 positive locally advanced G/GEJ cancer. This study also demonstrates the safety of immune checkpoint inhibitors in a conversional treatment approach.

CONCLUSION

We showed that a pathological complete response (pCR) can be obtained even with unresectable advanced GC through treatment with sintilimab combined with neoadjuvant chemotherapy and trastuzumab.

Trastuzumab Deruxtecan in Advanced Solid Tumors With Human Epidermal Growth Factor Receptor 2 Amplification Identified by Plasma Cell-Free DNA Testing: A Multicenter, Single-Arm, Phase II Basket Trial

PURPOSE

HERALD/EPOC1806 was conducted as a multicenter phase II trial assessing trastuzumab deruxtecan (T-DXd) therapy for patients with human epidermal growth factor receptor 2 (HER2)-amplified progressive stage solid tumors detected by cell-free DNA (cfDNA) testing.

PATIENTS AND METHODS

Patients exhibited advanced solid tumors with HER2 amplification that was identified via next-generation sequencing of cfDNA testing, without the requirement for immunohistochemical HER2 testing. The studied group was administered T-DXd at 5.4 mg/kg once every 3 weeks until onset of disease progression or intolerable toxicity.

RESULTS

Overall, 4,734 patients underwent cfDNA testing from December 2019 to January 2022, and 252 demonstrated HER2 amplification. Finally, the study included 62 patients with 16 cancer types with a median baseline plasma HER2 copy number (CN) of 8.55 (range, 2.4-73.9). Confirmed overall response rate (ORR) by investigator assessment was 56.5% (95% CI, 43.3 to 69.0), thus showing a value beyond the 5% threshold. Responses were evaluated for 13 cancer types, including KRAS-mutant colorectal (1/3), PIK3CA-mutant endometrial (5/6), and tissue HER2-negative gastric (1/2) cancers. Plasma HER2 CN above versus below the baseline median value did not differ for impact response; however, clearance of HER2 amplification in cfDNA on cycle 2 day 1 had higher response values compared with persistence. Median progression-free survival and response duration were 7.0 (95% CI, 4.9 to 9.7) and 8.8 (95% CI, 5.8 to 11.2) months, respectively, with the majority of complications being mild to moderate. Interstitial lung diseases were identified in 16 (26%) patients, including 14 patients with grade 1 disease, one patient with grade 2 disease, and one patient with grade 3 disease.

CONCLUSION

T-DXd treatment demonstrated high ORR with durable response in patients with advanced HER2-amplified solid tumors determined with cfDNA testing.

Targeting esophageal carcinoma: molecular mechanisms and clinical studies

Esophageal cancer (EC) is identified as a predominant health threat worldwide, with its highest incidence and mortality rates reported in China. The complex molecular mechanisms underlying EC, coupled with the differential incidence of esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) across various regions, highlight the necessity for in-depth research targeting molecular pathogenesis and innovative treatment strategies. Despite recent progress in targeted therapy and immunotherapy, challenges such as drug resistance and the lack of effective biomarkers for patient selection persist, impeding the optimization of therapeutic outcomes. Our review delves into the molecular pathology of EC, emphasizing genetic and epigenetic alterations, aberrant signaling pathways, tumor microenvironment factors, and the mechanisms of metastasis and immune evasion. We further scrutinize the current landscape of targeted therapies, including the roles of EGFR, HER2, and VEGFR, alongside the transformative impact of ICIs. The discussion extends to evaluating combination therapies, spotlighting the synergy between targeted and immune-mediated treatments, and introduces the burgeoning domain of antibody-drug conjugates, bispecific antibodies, and multitarget-directed ligands. This review lies in its holistic synthesis of EC's molecular underpinnings and therapeutic interventions, fused with an outlook on future directions including overcoming resistance mechanisms, biomarker discovery, and the potential of novel drug formulations.

Programmed death receptor-1/programmed death-ligand 1 inhibitors: Clinical progress and biomarker exploration in gastric cancer

Gastric cancer is one of the most common malignant tumours, with limited treatment options and poor prognosis in its advanced stages. In recent years, breakthroughs in tumour immunotherapy have led to immune checkpoint inhibitors becoming a new class of clinical oncology drugs. Programmed death receptor-1 (PD-1) and programmed death-ligand 1 (PD-L1) play significant roles in inhibiting T cell responses and tumour immune escape. PD-1/PD-L1 inhibitors can significantly improve the prognosis of patients with advanced gastric cancer. Moreover, the combination of administering PD-1/PD-L1 inhibitors along with chemotherapy, radiotherapy, targeted therapy, and other immunotherapies may further enhance therapeutic efficacy. However, some scientific issues need to be urgently resolved in the immunotherapy of gastric cancer, including the suboptimal efficacy of PD-1/PD-L1 inhibitor monotherapy, high incidence of immune-related adverse events, and the absence of definitive biomarkers for effectively screening treatment-sensitive populations. This article reviews the mechanism of action, therapeutic advances, adverse effects, and putative predictive biomarkers of PD-1/PD-L1 inhibitors in the treatment of advanced gastric cancer.

Analysis of the therapeutic effect and influencing factors on unresectable gastric cancer treated with conversion therapy

Background

Gastric cancer (GC) is one of the leading causes of cancer-related death in China, and with the extensive development of conversion therapy, the treatment of advanced unresectable gastric cancer (AUGC) patients has ushered in a new dawn. This study aimed to analyze the efficacy of conversion therapy in AUGC patients and explored the relevant factors affecting the efficacy.

Method

We collected information from GC patients who received conversion therapy from this center and designed a retrospective study.

Results

We collected relevant clinical data from 160 patients with AUGC. A total of 120 patients who underwent routine R0 resection were identified as conversion cases. A total of 25 patients (15.6%) achieved pCR, 92 patients (57.5%) achieved objective response rate (ORR), 140 patients (87.5%) achieved disease control rate (DCR), and 20 cases (12.5%) observed tumor progression. There were 86 patients who achieved pathological downgrading, with a total downgrading rate of 53.8%. Among the 160 patients, 37 patients (23.1%) had postoperative complications of varying degrees. A total of 72 patients (45.0%) had tumor recurrence/progression at the end of follow-up. The last chemotherapy and surgery (CST) (OR = 1.046, 95% CI 1.013-1.081, p = 0.006), tumor invasion (OR = 32.096, 95% CI 5.091-202.349, p < 0.001), and distant metastasis (OR = 7.050, 95% CI 1.888-26.323, p = 0.004) were independent factors influencing the efficacy of conversion therapy.

Conclusion

Conversion therapy may have a good therapeutic efficacy for AUGC, and some clinical factors affect the efficacy response.

The addition of PD-1 inhibitor overcame trastuzumab resistance in patients with HER2 positive, PD-L1 negative metastatic gastric cancer: Case report and review of literature

Gastric cancer (GC) is a malignancy with poor prognosis and high heterogeneity. For HER2-positive, PD-L1 negative metastatic GC patients, chemotherapy plus trastuzumab is the first-line therapy. However, such patients soon acquired resistance to treatment, especially to trastuzumab during the treatment. Improving the therapeutic resistance of HER2-positive, PD-L1 negative metastatic GC is still a dilemma. We present the case of a metastatic GC patient with HER2-positive and PD-L1-negative expression who suffered progression after a short remission with trastuzumab plus chemotherapy. The patient exhibited strong heterogeneity in the primary and metastatic lesions. His resistance to trastuzumab was overcome after the addition of a PD-1 inhibitor, after which he received a durable response for more than 8 months. In HER2-positive, PD-L1-negative metastatic GC, the addition of PD-1 inhibitors after first-line chemotherapy and trastuzumab treatment resistance may be an option.

HER2-targeted therapies beyond breast cancer - an update

The receptor tyrosine-kinase HER2 (also known as ErbB2) is a well-established therapeutic target in patients with breast or gastric cancer selected on the basis of HER2 overexpression on immunohistochemistry and/or ERBB2 amplification on in situ hybridization. With advances in cancer molecular profiling and increased implementation of precision medicine approaches into oncology practice, actionable HER2 alterations in solid tumours have expanded to include ERBB2 mutations in addition to traditional HER2 overexpression and ERBB2 amplification. These various HER2 alterations can be found in solid tumour types beyond breast and gastric cancer, although few HER2-targeted therapeutic options have been established for the other tumour types. Nevertheless, during the 5 years since our previous Review on this topic was published in this journal, obvious and fruitful progress in the development of HER2-targeted therapies has been made, including new disease indications, innovative drugs with diverse mechanisms of action and novel frameworks for approval by regulatory authorities. These advances have culminated in the recent histology-agnostic approval of the anti-HER2 antibody-drug conjugate trastuzumab deruxtecan for patients with HER2-overexpressing solid tumours. In this new Review, we provide an update on the current development landscape of HER2-targeted therapies beyond breast cancer, as well as anticipated future HER2-directed treatment strategies to overcome resistance and thereby improve efficacy and patient outcomes.

HER-2 directed therapies across gastrointestinal tract cancers - A new frontier

Gastrointestinal (GI) cancers are common and in the metastatic setting they have a poor prognosis. The current mainstay of treatment of GI cancers is chemotherapy; however, the biomarker-directed treatment landscape is evolving. HER-2 is overexpressed in a portion of GI cancers and is an emerging target for therapy, with recent FDA tumor agnostic approval for trastuzumab deruxtecan. Testing for HER-2 expression is not standardized across GI cancers, methodology requires further optimization and standardization as HER-2 targeted therapy emerges into the treatment landscape. There is established rationale for use of HER-2 targeted therapy in first line treatment of metastatic gastric cancer, and emerging evidence with variable benefit in bile duct, pancreatic and colorectal cancers.

Research progress and future directions of immune checkpoint inhibitor combination therapy in advanced gastric cancer

In recent years, with the continuous development of molecular immunology, immune checkpoint inhibitors (ICIs) have also been widely used in the treatment of gastric cancer, but they still face some challenges: The first is that only some people can benefit, the second is the treatment-related adverse events (TRAEs) that occur during treatment, and the third is the emergence of varying degrees of drug resistance with long-term use. How to overcome these challenges, combined therapy based on ICIs has become one of the important strategies. This article summarizes the clinical application of ICIs combined with chemotherapy, targeted therapy, radiotherapy, photodynamic therapy, thermotherapy, immune adjuvant, and dual immunotherapy and discusses the mechanism, and also summarizes the advantages and disadvantages of the current combination modalities and the potential research value. The aim of this study is to provide more and more optimized combination regimen for ICI combined therapy in patients with advanced gastric cancer and to provide reference for clinical and scientific research.

Emerging Therapeutic Targets and Future Directions in Advanced Gastric Cancer: A Comprehensive Review

Metastatic gastric cancer (GC) still represents a critical clinical challenge, with limited treatment options and a poor prognosis. Most patients are diagnosed at advanced stages, limiting the chances of surgery and cure. The identification of molecular targets and the possibility of combining immune checkpoint inhibitors with chemotherapy have recently reshaped the therapeutic landscape of metastatic gastric cancer. The new classification of gastric cancer, mainly based on immunologic and molecular criteria such as programmed cell death 1 (PD-1), microsatellite instability (MSI), and human epidermal growth factor receptor 2 (HER2), has made it possible to identify and differentiate patients who may benefit from immunotherapy, targeted therapy, or chemotherapy alone. All relevant and available molecular and immunological targets in clinical practice for the systemic treatment of this disease are presented. Particular attention is given to possible future approaches, including circulating tumor DNA (ctDNA) for therapeutic monitoring, new targeting agents against molecular pathways such as fibroblast growth factor receptor (FGFR) and MET, chimeric antigen receptor (CAR)-T cells, and cancer vaccines. This review aims to provide a comprehensive understanding of current targets in advanced gastric cancer and to offer valuable insights into future directions of research and clinical practice in this challenging disease.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

Advances in Human Epidermal Growth Factor Receptor 2-Targeted Therapy in Upper Gastrointestinal Cancers

The Trastuzumab for Gastric Cancer (ToGA) trial marked a pivotal moment in the adoption of trastuzumab for treating advanced human epidermal growth factor receptor 2 (HER2)-positive esophagogastric (EG) cancer. The KEYNOTE-811 trial brought to light the synergistic effect of immune modulation and HER2 targeting. Additionally, the emergence of trastuzumab deruxtecan (T-DXd) highlighted the potential of new pharmaceutical technologies to extend response, particularly for patients who have advanced beyond initial HER2-targeted therapies. This review aims to navigate through both the successes and challenges encountered historically, as well as promising current trials on innovative and transformative therapeutic strategies, including promising first-in-class and novel first-in-human agents.

Progress of PD-1/PD-L1 inhibitor combination therapy in immune treatment for HER2-positive tumors

BACKGROUND

Patients with HER2-positive cancers often face a poor prognosis, and treatment regimens containing anti-HER2 have become the first-line treatment options for breast and gastric cancers. However, these approaches are faced with significant challenges in terms of drug resistance. Hence, it is crucial to explore precise treatment strategies aimed at improving survival outcomes.

ADVANCEMENTS IN TREATMENT

Over the past few years, there has been rapid advancement in the realm of tumor therapy, particularly with the swift progress of immune checkpoint inhibitors, including PD-1/PD-L1 inhibitors. They exert anti-tumor effects by disrupting immune-suppressive factors within the tumor microenvironment. However, monotherapy with PD-1/PD-L1 inhibitors has several limitations. Consequently, numerous studies have explored combinatorial immunotherapeutic strategies and demonstrated highly promising avenues of development.

OBJECTIVE

This article aims to review the clinical trials investigating PD-1/PD-L1 inhibitor combination therapy for HER2-positive tumors. Additionally, it provides a summary of ongoing trials evaluating the efficacy and safety of these combined treatments, with the intention of furnishing valuable insights for the clinical management of HER2-positive cancer.

CONCLUSION

Combinatorial immunotherapeutic strategies involving PD-1/PD-L1 inhibitors hold considerable promise in the treatment of HER2-positive tumors. Continued research efforts and clinical trials are warranted to elucidate optimal treatment regimens that maximize therapeutic benefits while minimizing adverse effects.

Recent Progress in Treatment for HER2-Positive Advanced Gastric Cancer

Human epidermal receptor (HER) 2-positive advanced gastric cancer is one of the major subtypes of gastric cancer, accounting for ~20% of all cases. Although combination therapy with trastuzumab and chemotherapy provides meaningful survival benefit, clinical trials targeting HER2 have failed to demonstrate clinical benefits in first- or subsequent-line treatment. Trastuzumab deruxtecan, an antibody-drug conjugate, has shown positive results even in later-line treatment and has become new standard treatment. In first-line therapy, combination therapy with pembrolizumab and trastuzumab plus chemotherapy demonstrated a dramatic response rate. Therefore, the FDA rapidly approved it without waiting for the results of survival time. The emergence of combination therapy including immunotherapy with HER2-targeting agents and the development of HER2 targeting agents with or without immunotherapy have been advancing for treating HER2-positive gastric cancer. In this review, we will discuss the current status of treatment development and future perspectives for HER2-positive gastric cancer.

Efficacy and safety of bispecific antibodies vs. immune checkpoint blockade combination therapy in cancer: a real-world comparison

Emerging tumor immunotherapy methods encompass bispecific antibodies (BSABs), immune checkpoint inhibitors (ICIs), and adoptive cell immunotherapy. BSABs belong to the antibody family that can specifically recognize two different antigens or epitopes on the same antigen. These antibodies demonstrate superior clinical efficacy than monoclonal antibodies, indicating their role as a promising tumor immunotherapy option. Immune checkpoints are also important in tumor immunotherapy. Programmed cell death protein-1 (PD-1) is a widely acknowledged immune checkpoint target with effective anti-tumor activity. PD-1 inhibitors have demonstrated notable therapeutic efficacy in treating hematological and solid tumors; however, more than 50% of patients undergoing this treatment exhibit a poor response. However, ICI-based combination therapies (ICI combination therapies) have been demonstrated to synergistically increase anti-tumor effects and immune response rates. In this review, we compare the clinical efficacy and side effects of BSABs and ICI combination therapies in real-world tumor immunotherapy, aiming to provide evidence-based approaches for clinical research and personalized tumor diagnosis and treatment.

Targeting HER2 in Gastroesophageal Adenocarcinoma: Molecular Features and Updates in Clinical Practice

Gastroesophageal adenocarcinoma (GEA) is one of the principal causes of death related to cancer globally. Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor which is found to be overexpressed or amplified in approximately 20% of GEA cases. In GEA, the identification of HER2-positive status is crucial to activate a specific anti-HER2 targeted therapy. The landmark ToGA trial demonstrated the superiority of adding trastuzumab to platinum-based chemotherapy, becoming the first-line standard of treatment. However, unlike breast cancer, the efficacy of other anti-HER2 drugs, such as lapatinib, pertuzumab, and T-DM1, has failed to improve outcomes in advanced and locally advanced resectable GEA. Recently, the combination of trastuzumab with pembrolizumab, along with chemotherapy, and the development of trastuzumab deruxtecan, with its specific bystander activity, demonstrated improved outcomes, renewing attention in the treatment of this disease. This review will summarise historical and emerging therapies for the treatment of HER2-positive GEA, with a section dedicated to the HER2 molecular pathway and the use of novel blood biomarkers, such as circulating tumour DNA and circulating tumour cells, which may be helpful in the future to guide treatment decisions.

Gastric cancer with brain metastasis: from molecular characteristics and treatment

Gastric cancer is one of the cancers with increasing incidence and ranks fourth globally among the most frequent causes of cancer-related mortality. Early gastric cancer is often asymptomatic or presents with atypical symptoms, and the majority of patients present with advanced disease upon diagnosis. Brain metastases are present in approximately 1% of gastric cancer patients at the time of diagnosis, which significantly contributed to the overall mortality of the disease worldwide. Conventional therapies for patients with brain metastases remain limited and the median overall survival of patients is only 8 months in advanced cases. Recent studies have improved our understanding of the molecular mechanisms underlying gastric cancer brain metastases, and immunotherapy has become an important treatment option in combination with radiotherapy, chemotherapy, targeted therapy and surgery. This review aims to provide insight into the cellular processes involved in gastric cancer brain metastases, discuss diagnostic approaches, evaluate the integration of immune checkpoint inhibitors into treatment and prognosis, and explore the predictive value of biomarkers in immunotherapy.

Expression and correlation of PD-L1 and HER2 in oesophageal squamous cell carcinoma

AIMS

In recent years, patients with programmed cell death-Ligand 1 (PD-L1)-positive oesophageal squamous cell carcinoma (OSCC) have been able to benefit from immunotherapy. However, method for improving the treatment efficacy of PD-L1-positive patients is a problem that needs further consideration. Studies on the relationship between human epidermal growth factor receptor 2 (HER2) and PD-L1 expression have recently been reported in certain cancers, but the relationship between PD-L1 and HER2 expression in OSCC is still unclear.

METHODS

A total of 263 patients with OSCC were included in the study. PD-L1 protein expression and HER2 protein expression were analysed by immunohistochemistry (IHC), and fluorescence in situ hybridisation (FISH) was performed to assess HER2 gene amplification. The significance of differences between HER2 status, PD-L1 status and clinicopathological parameters was assessed. The relationship between PD-L1 status and HER2 status was examined.

RESULTS

Of the 263 OSCC cases, the PD-L1-positive expression rates were 39.2% and 77.2% in OSCC for Tumour Proportion Score (TPS) and Combined Positive Score (CPS), respectively, and PD-L1 expression was associated with the degree of tumour differentiation. The HER2 expression was positive in 24% (63/263) of cases based on IHC and FISH. HER2 expression was not significantly associated with clinicopathological characteristics. PD-L1 TPS expression and CPS expression were significantly positively correlated with HER2 expression in OSCC.

CONCLUSIONS

PD-L1 expression was significantly positively correlated with HER2 expression in OSCC. The results provide valuable insight for the future application of HER2-targeted therapy combined with immunotherapy in OSCC.

New clinical trial design in precision medicine: discovery, development and direction

In the era of precision medicine, it has been increasingly recognized that individuals with a certain disease are complex and different from each other. Due to the underestimation of the significant heterogeneity across participants in traditional "one-size-fits-all" trials, patient-centered trials that could provide optimal therapy customization to individuals with specific biomarkers were developed including the basket, umbrella, and platform trial designs under the master protocol framework. In recent years, the successive FDA approval of indications based on biomarker-guided master protocol designs has demonstrated that these new clinical trials are ushering in tremendous opportunities. Despite the rapid increase in the number of basket, umbrella, and platform trials, the current clinical and research understanding of these new trial designs, as compared with traditional trial designs, remains limited. The majority of the research focuses on methodologies, and there is a lack of in-depth insight concerning the underlying biological logic of these new clinical trial designs. Therefore, we provide this comprehensive review of the discovery and development of basket, umbrella, and platform trials and their underlying logic from the perspective of precision medicine. Meanwhile, we discuss future directions on the potential development of these new clinical design in view of the "Precision Pro", "Dynamic Precision", and "Intelligent Precision". This review would assist trial-related researchers to enhance the innovation and feasibility of clinical trial designs by expounding the underlying logic, which be essential to accelerate the progression of precision medicine.

Targeting HER2-positive breast cancer cells by a combination of dasatinib and BMS-202: Insight into the molecular pathways

BACKGROUND

Recent investigations have reported the benefits of using a tyrosine kinase inhibitor, dasatinib (DA), as well as programmed death-ligand 1 (PD-L1) inhibitors in the management of several solid tumors, including breast cancer. Nevertheless, the outcome of the combination of these inhibitors on HER2-positive breast cancer is not explored yet.

METHODS

Herein, we investigated the impact of DA and PD-L1 inhibitor (BMS-202) combination on HER2-positive breast cancer cell lines, SKBR3 and ZR75.

RESULTS

Our data reveal that the combination significantly inhibits cell viability of both cancer cell lines as compared to monotreatment. Moreover, the combination inhibits epithelial-mesenchymal transition (EMT) progression and reduces cancer cell invasion by restoring E-cadherin and β-catenin expressions and loss of vimentin, major biomarkers of EMT. Additionally, the combination reduces the colony formation of both cell lines in comparison with their matched control. Also, the combination considerably inhibits the angiogenesis of the chorioallantoic membrane model compared with monotreatment. Molecular pathway analysis of treated cells shows that this combination blocks HER2, AKT, β-catenin, and JNK1/2/3 activities.

CONCLUSION

Our findings implicate that a combination of DA and BMS-202 could have a significant impact on the management of HER2-positive breast cancer.

HER2-targeted therapies in cancer: a systematic review

Abnormal alterations in human epidermal growth factor receptor 2 (HER2, neu, and erbB2) are associated with the development of many tumors. It is currently a crucial treatment for multiple cancers. Advanced in molecular biology and further exploration of the HER2-mediated pathway have promoted the development of medicine design and combination drug regimens. An increasing number of HER2-targeted drugs including specific monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have been approved by the U.S. Food and Drug Administration. The emergence of ADCs, has significantly transformed the treatment landscape for various tumors, such as breast, gastric, and bladder cancer. Classic monoclonal antibodies and novel TKIs have not only demonstrated remarkable efficacy, but also expanded their indications, with ADCs in particular exhibiting profound clinical applications. Moreover the concept of low HER2 expression signifies a breakthrough in HER2-targeted therapy, indicating that an increasing number of tumors and patients will benefit from this approach. This article, provides a comprehensive review of the underlying mechanism of action, representative drugs, corresponding clinical trials, recent advancements, and future research directions pertaining to HER2-targeted therapy.

Ubiquilin-4 induces immune escape in gastric cancer by activating the notch signaling pathway

PURPOSE

We aimed to investigate the role of ubiquilin-4 in predicting the immunotherapy response in gastric cancer.

METHODS

Retrospective RNA-sequencing and immunohistochemical analysis were performed for patients with gastric cancer who received programmed death-1 blockade therapy after recurrence. Multiplex immunohistochemistry identified immune cell types in gastric cancer tissues. We used immunocompetent 615 mice and immunodeficient nude mice to perform tumorigenic experiments.

RESULTS

Ubiquilin-4 expression was significantly higher in responders (p < 0.05, false discovery rate > 2.5) and showed slight superiority over programmed death ligand 1 in predicting programmed death-1 inhibitor therapy response (area under the curve: 87.08 vs. 72.50). Ubiquilin-4-high patients exhibited increased CD4+ and CD8+ T cells, T follicular helper cells, monocytes, and macrophages. Ubiquilin-4-overexpressed mouse forestomach carcinoma cells showed significantly enhanced growth in immunocompetent mice but not in immunodeficient mice. Upregulation or downregulation of ubiquilin-4 synergistically affected programmed death ligand 1 at the protein and messenger RNA levels. Functional enrichment analysis revealed significant enrichment of the Notch, JAK-STAT, and WNT signaling pathways in ubiquilin-4-high gastric cancers. Ubiquilin-4 promoted Numb degaration, activating the Notch signaling pathway and upregulating programmed death ligand 1.

CONCLUSIONS

Ubiquilin-4 may contribute to immune escape in gastric cancer by upregulating programmed death ligand 1 expression in tumor cells through Notch signaling activation. Thus, ubiquilin-4 could serve as a predictive marker for programmed death ligand 1 inhibitor therapy response in gastric cancer.

Emerging Targets for Systemic Treatment of Gastric Cancer: HER2 and Beyond

In recent years, remarkable progress has been made in the molecular profiling of gastric cancer. This progress has led to the development of various molecular classifications to uncover subtype-specific dependencies that can be targeted for therapeutic interventions. Human epidermal growth factor receptor 2 (HER2) is a crucial biomarker for advanced gastric cancer. The recent promising results of novel approaches, including combination therapies or newer potent agents such as antibody-drug conjugates, have once again brought attention to anti-HER2 targeted treatments. In HER2-negative diseases, the combination of cytotoxic chemotherapy and programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors has become the established standard of care in first-line settings. In the context of gastric cancer, potential biomarkers such as PD-L1 expression, Epstein-Barr virus, microsatellite instability, and tumor mutational burden are being considered for immunotherapy. Recently, promising results have been reported in studies on anti-Claudin18.2 and fibroblast growth factor receptor 2 treatments. Currently, many ongoing trials are aimed at identifying potential targets using novel approaches. Further investigations will be conducted to enhance the progress of these therapies, addressing challenges such as primary and acquired resistance, tumor heterogeneity, and clonal evolution. We believe that these efforts will improve patient prognoses. Herein, we discuss the current evidence of potential targets for systemic treatment, clinical considerations, and future perspectives.

Gastric Cancer Signaling Pathways and Therapeutic Applications

Gastric cancer (GC) is a prevalent malignant tumor and ranks as the second leading cause of death among cancer patients worldwide. Due to its hidden nature and difficulty in detection, GC has a high incidence and poor prognosis. Traditional treatment methods such as systemic chemotherapy, radiotherapy, and surgical resection are commonly used, but they often fail to achieve satisfactory curative effects, resulting in a very low 5-year survival rate for GC patients. Currently, targeted therapy and immunotherapy are prominent areas of research both domestically and internationally. These methods hold promise for the treatment of GC. This article focuses on the signaling pathways associated with the development of GC, as well as the recent advancements and applications of targeted therapy and immunotherapy. The aim is to provide fresh insights for the clinical treatment of GC.

Optimizing the Continuum of Care in Gastric Cancer

Gastric cancer (GC) still ranks as the fifth most common malignancy and the fourth leading cause of cancer-related death worldwide. Despite the recent progress in the therapeutic algorithm of the advanced disease with the advent of immune checkpoint inhibitors (ICIs) and next-generation HER2-directed therapies, survival rates remain poor, with a median survival hardly exceeding 12 months. Furthermore, only 40% of patients remain eligible for second- and later-line treatments due to the aggressiveness of the disease and the rapid deterioration of performance status (PS). Thus, current research is focusing either on the identification of novel treatment options or the development of personalized strategies to optimize the continuum of care and ultimately improve patients' outcome. In this article, we provide an overview of the current treatment landscape for advanced GC with a particular emphasis on later-line treatments and outline novel perspectives on the horizon.

Immune checkpoint inhibitors and cellular immunotherapy for advanced gastric, gastroesophageal cancer: a long pathway

Although the incidence rate and mortality of gastric/gastroesophageal cancer (G/GEJC) are declining globally, G/GEJC remains a health issue in East Asia. When diagnosed as advanced stage, treatment after serial lines of chemotherapy is limited, with a median overall survival of less than 1 year. Immunotherapy, including immune checkpoint inhibitors (ICIs) and cellular immunotherapy, has changed the prospects of cancer therapy by reversing immune suppression in the tumor microenvironment. As part of this review, we enumerated the clinical uses of ICIs related to the immunosuppressive signaling axis PD-1/PD-L1 and CTLA-4/B7. ICIs were initially approved as a secondary treatment option for patients with severe pretreating advanced gastric and gastroesophageal cancer (AG/GEJC). Till now, it has become the mainstream therapy in combination with chemotherapy and targeted therapy for patients identified by biomarkers. Numerous evidence showed microsatellite instability (MSI), programmed cell death ligand 1 (PD-L1) expression, tumor mutation burden (TMB) and Epstein-Barr virus (EBV) status might be indicative to the use of ICIs. In addition, we discussed the current limitations and prospects of ICIs in AG/GGEJC, as well as the first clinical application of novel CAR-T cell therapies.

Immunology and immunotherapy in gastric cancer

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide. As the diagnosis of early gastric cancer is difficult, most patients are at a late stage of cancer progression when diagnosed. The current therapeutic approaches based on surgical or endoscopic resection and chemotherapy indeed improve patients' outcomes. Immunotherapy based on immune checkpoint inhibitors has opened a new era for cancer treatment, and the immune system of the host is reshaped to combat tumor cells and the strategy differs according to the patient's immune system. Thus, an in-depth understanding of the roles of various immune cells in the progression of gastric cancer is beneficial to application for immunotherapy and the discovery of new therapeutic targets. This review describes the functions of different immune cells in gastric cancer development, mainly focusing on T cells, B cells, macrophages, natural killer cells, dendritic cells, neutrophils as well as chemokines or cytokines secreted by tumor cells. And this review also discusses the latest advances in immune-related therapeutic approaches such as immune checkpoint inhibitors, CAR-T or vaccine, to reveal potential and promising strategies for gastric cancer treatment.

Human Epidermal Growth Factor Receptor-2 Gastric Adenocarcinoma: Expanding Therapy of a Recognized Target

Human epidermal growth factor receptor-2 (HER2) is a well-known cancer target. Many HER2-targeted agents are marketed and being investigated. Unfortunately, these therapies lack consistent responses and outcomes amongst different tumors. Questions remain as to why HER2 biology is different in different tumor types. Gastric adenocarcinomas (GACs) demonstrate both intra- and inter-tumor HER2 expression heterogeneity and show discordance amongst primary and metastatic disease sites. This creates barriers in determining HER2 agents' effectiveness and contributes to the failure of some HER2-targeted agents in the treatment of HER2-positive advanced GACs. Trastuzumab deruxtecan, an antibody drug conjugate of trastuzumab with a topoisomerase inhibitor, was recently approved for the treatment of refractory HER2-positive advanced GAC patients. There are exciting and newer therapies under investigation. Examining resistance patterns (both adaptive and acquired) along with establishing a better understanding of the intra- and inter-tumor heterogeneity is necessary to ensure successful progress. Here we review the current status of HER2-targeted therapy in GACs. We additionally review newer therapies under investigation and their potential role in HER2 GACs.

Predictive Biomarkers for Immunotherapy in Gastric Cancer: Current Status and Emerging Prospects

Gastric cancer presents substantial management challenges, and the advent of immunotherapy has ignited renewed hope among patients. Nevertheless, a significant proportion of patients do not respond to immunotherapy, and adverse events associated with immunotherapy also occur on occasion, underscoring the imperative to identify suitable candidates for treatment. Several biomarkers, including programmed death ligand-1 expression, tumor mutation burden, mismatch repair status, Epstein-Barr Virus infection, circulating tumor DNA, and tumor-infiltrating lymphocytes, have demonstrated potential in predicting the effectiveness of immunotherapy in gastric cancer. However, the quest for the optimal predictive biomarker for gastric cancer immunotherapy remains challenging, as each biomarker carries its own limitations. Recently, multi-omics technologies have emerged as promising platforms for discovering novel biomarkers that may help in selecting gastric cancer patients likely to respond to immunotherapy. The identification of reliable predictive biomarkers for immunotherapy in gastric cancer holds the promise of enhancing patient selection and improving treatment outcomes. In this review, we aim to provide an overview of clinically established biomarkers of immunotherapy in gastric cancer. Additionally, we introduce newly reported biomarkers based on multi-omics studies in the context of gastric cancer immunotherapy, thereby contributing to the ongoing efforts to refine patient stratification and treatment strategies.

The History and Development of HER2 Inhibitors

HER2 is highly expressed in a variety of malignant tumors and affects the prognosis of patients, making it a highly sensitive target for cancer therapy. Since the approval of the first HER2 inhibitor, trastuzumab, in 1998, HER2-targeted drugs have rapidly evolved. Currently, targeting HER2 drugs mainly include monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs). This article reviews the development of HER2 inhibitors for various tumors over the past 20 years.

Immunotherapeutic strategy in the management of gastric cancer: molecular profiles, current practice, and ongoing trials

Gastric cancer (GC) is the one of the most commonly solid cancer worldwide. Although under the aggressive treatment, the poor clinical outcomes of patients with GCs have not been improved. Current studies emphasized that targeting therapies or immune response-based therapeutic strategy may be a potential approach to improve the clinical outcomes. Moreover, accumulative evidence has reported the increasing expression of PD-L1 expression in GC cells and highlighted its role in the tumor progression. Currently, great development has been established in the immune checkpoint inhibitors (ICIs) and further changed the clinical practice of GC treatment and prognosis. In addition, the combination therapies with targeting therapy or traditional therapies are expected to push the development of immunotherapies. In our present review, we predominantly focus on the biomarkers and molecular profiles for immunotherapies in GCs and highlight the role and administration of ICIs-based immunotherapeutic strategies against the GCs.

Advances in targeted therapy and immunotherapy for esophageal cancer

ABSTRACT

Esophageal cancer (EC) is one of the most common aggressive malignant tumors in the digestive system with a severe epidemiological situation and poor prognosis. The early diagnostic rate of EC is low, and most EC patients are diagnosed at an advanced stage. Multiple multimodality treatments have gradually evolved into the main treatment for advanced EC, including surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. And the emergence of targeted therapy and immunotherapy has greatly improved the survival of EC patients. This review highlights the latest advances in targeted therapy and immunotherapy for EC, discusses the efficacy and safety of relevant drugs, summarizes related important clinical trials, and tries to provide references for therapeutic strategy of EC.

Targeted and Immunotherapy Approaches in HER2-Positive Gastric and Gastroesophageal Junction Adenocarcinoma: A New Era

HER2-targeted therapy with the HER2 monoclonal antibody trastuzumab has achieved impressive outcomes in the first-line settings of patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma overexpressing HER2. However, considering that a substantial proportion of those patients eventually relapses, as well as the relatively limited performance of those agents in second-line settings, a deeper understanding of resistance mechanisms is needed for enhanced guidance for patients' therapeutic selection in the second-line setting and beyond. In this review, we highlight trastuzumab's (HER2-targeting agent) performance in patients with gastric or GEJ cancer, with insight into mechanisms of resistance. We also discuss the new integration of PD-1 inhibitor pembrolizumab into the trastuzumab for gastric cancer frontline regimen, the latest addition of trastuzumab deruxtecan to the treatment armamentarium, and the potential of pipeline HER2-targeting approaches and combinations in patients with gastric or GEJ adenocarcinoma.

Novel Biomarkers of Gastric Cancer: Current Research and Future Perspectives

Gastric cancer is a heterogeneous disease with diverse histological and genomic subtypes, making it difficult to demonstrate treatment efficacy in clinical trials. However, recent efforts have been made to identify molecular biomarkers with prognostic and predictive implications to better understand the broad heterogeneity of gastric cancer and develop effective targeted therapies for it. HER2 overexpression, HER2/neu amplification, MSI-H, and PD-L1+ are predictive biomarkers in gastric cancer, and a growing number of clinical trials based on novel biomarkers have demonstrated the efficacy of targeted therapies alone or in combination with conventional chemotherapy. Enrichment design clinical trials of targeted therapies against FGFR2b and claudin 18.2 have demonstrated efficacy in unresectable advanced gastric cancer. Nonetheless, it is essential to continuously validate promising molecular biomarkers and introduce them into clinical practice to optimize treatment selection and improve patient outcomes. In this review, we focused on established (PD-L1, HER2, MSI) and emerging biomarkers (FGFR2, CLDN18.2) in gastric cancer, their clinical significance, detection methods, limitations, and molecular agents that target these biomarkers.

Targeted Therapies and Developing Precision Medicine in Gastric Cancer

Gastric cancer is an aggressive disease with survival remaining poor in the advanced setting. More than a decade after the first targeted treatment was approved, still only HER2, MSI and PDL-1 status have reached everyday practice in terms of guiding treatment options for these patients. However, various new targets and novel treatments have recently been investigated and have shown promise in improving survival outcomes. In this review, we will summarise previous and currently ongoing studies on predictive biomarkers, possible new targeted treatments, potential reasons for conflicting trial results and hope for the future of precision medicine in gastric cancer.

Gastric cancer treatment: recent progress and future perspectives

Gastric cancer (GC) is one of the most common malignancies worldwide. Most patients are diagnosed at advanced stages due to the subtle symptoms of earlier disease and the low rate of regular screening. Systemic therapies for GC, including chemotherapy, targeted therapy and immunotherapy, have evolved significantly in the past few years. For resectable GC, perioperative chemotherapy has become the standard treatment. Ongoing investigations are exploring the potential benefits of targeted therapy or immunotherapy in the perioperative or adjuvant setting. For metastatic disease, there have been notable advancements in immunotherapy and biomarker-directed therapies recently. Classification based on molecular biomarkers, such as programmed cell death ligand 1 (PD-L1), microsatellite instability (MSI), and human epidermal growth factor receptor 2 (HER2), provides an opportunity to differentiate patients who may benefit from immunotherapy or targeted therapy. Molecular diagnostic techniques have facilitated the characterization of GC genetic profiles and the identification of new potential molecular targets. This review systematically summarizes the main research progress in systemic treatment for GC, discusses current individualized strategies and presents future perspectives.