Trastuzumab Combined With Ramucirumab and Paclitaxel in Patients With Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Advanced Gastric or Gastroesophageal Junction Cancer

Zanidatamab monotherapy or combined with chemotherapy in HER2-expressing gastroesophageal adenocarcinoma: a phase 1 trial

There is a need for novel therapies for patients with previously treated HER2-positive gastroesophageal adenocarcinoma (GEA). This phase 1 (NCT02892123) dose-escalation and expansion trial evaluated zanidatamab (a dual HER2-targeted bispecific antibody) ± chemotherapy in previously treated patients with HER2-expressing, locally advanced/metastatic cancers. Here, we report the outcomes for GEA cohorts receiving zanidatamab monotherapy or with chemotherapy (paclitaxel or capecitabine). The primary endpoint was safety and tolerability. Secondary endpoints were objective response rate (ORR), disease control rate, progression-free survival, pharmacokinetics, and immunogenicity. Seventy patients were enrolled (n = 29 monotherapy; n = 41 combination therapy); most received prior HER2-targeted agents (monotherapy, 93%; combination therapy, 95%). With monotherapy, 69% of patients had any-grade treatment-related AEs (TRAEs); 17% had grade ≥ 3 TRAEs. The most common any-grade TRAEs were diarrhea (41%) and infusion-related reactions (24%). With combination therapy, 98% of patients had any-grade TRAEs; 51% had grade ≥ 3 TRAEs. The most common any-grade TRAEs were diarrhea (68%) and fatigue (44%). Confirmed ORR was 32.1% (95% confidence interval [CI] 15.9-52.4) with monotherapy and 48.6% (95% CI 31.9-65.6) with combination therapy. In heavily pre-treated patients with HER2-expressing GEA, zanidatamab ± chemotherapy had a manageable safety profile and promising antitumor activity.

Current status and perspectives of esophageal cancer: a comprehensive review

Esophageal cancer (EC) continues to be a significant global health concern, with two main subtypes: esophageal squamous cell carcinoma and esophageal adenocarcinoma. Prevention and changes in etiology, improvements in early detection, and refinements in the treatment have led to remarkable progress in the outcomes of EC patients in the past two decades. This seminar provides an in-depth analysis of advances in the epidemiology, disease biology, screening, diagnosis, and treatment landscape of esophageal cancer, focusing on the ongoing debate surrounding multimodality therapy. Despite significant advancements, EC remains a deadly disease, underscoring the need for continued research into early detection methods, understanding the molecular mechanisms, and developing effective treatments.

Nab-paclitaxel combined with cadonilimab (AK104) as second-line treatment for advanced gastric cancer: protocol for a phase II prospective, multicenter, single-arm clinical trial

Background

Gastric cancer (GC) is one of the most prevalent malignant tumors worldwide, often diagnosed at an advanced stage with a poor prognosis. Paclitaxel, nab-paclitaxel, and irinotecan, either as monotherapies or in combination with ramucirumab, are currently standard second-line treatments for GC. However, the efficacy of these therapies is limited, necessitating the development of new combination strategies to improve response rates. Immune checkpoint inhibitors (ICIs) have shown success in first-line treatment for advanced GC, leading to interest in immune rechallenge strategies for second-line treatment. Re-challenging patients with ICIs after progression on first-line treatment may restore immune responses and provide additional clinical benefit. Recently, cadonilimab (AK104), a bispecific antibody targeting PD-1 and CTLA-4, has demonstrated promising antitumor activity when combined with chemotherapy in advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma. However, the efficacy and safety of nab-paclitaxel combined with AK104 for the treatment of advanced GC remain unclear. Furthermore, identifying predictive biomarkers of efficacy is essential to developing personalized treatment strategies. This study aims to explore the safety and efficacy of nab-paclitaxel combined with AK104 as a second-line treatment for patients who have progressed after first-line chemoimmunotherapy, focusing on evaluating the therapeutic effect of ICIs rechallenge in gastric cancer.

Methods

This is a prospective, multicenter, open-label, single-arm Phase II clinical study. Eligible patients were histologically or cytologically diagnosed with unresectable recurrent or metastatic GC, failed first-line chemotherapy in combination with immune checkpoint inhibitor, aged between 18-75 years old, expected survival ≥3 months, and with a physical status of 0 or 1 in the Eastern Cooperative Cancer Group (ECOG). Enrolled patients will receive intravenous cadonilimab (AK104) 6 mg/kg on days 1, and 15, and intravenous nab-paclitaxel 100 mg/m2 every four weeks on days 1, 8, and 15. The primary endpoints were objective response rate (ORR), and secondary endpoints were disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). The exploratory objective was to identify biomarkers associated with efficacy, mechanism of action, and safety. A total of 59 participants were planned to be recruited using Simon's two-stage design. The trial was initiated in June 2024 in China.

Discussion

This study is the first prospective trial to evaluate the combination of nab-paclitaxel and cadonilimab as second-line treatment after first-line chemoimmunotherapy failure. By investigating immune rechallenge, it aims to reactivate anti-tumor immune responses and improve clinical outcomes in GC patients. The exploration of predictive biomarkers, such as ctDNA, TMB, MSI, PD-L1 expression, TIL profiles, and gut microbiota, will help personalize treatment and identify patients most likely to benefit from immune rechallenge. This trial could provide valuable insights into overcoming immune resistance and contribute to developing a promising second-line therapeutic strategy for advanced GC.

Clinical trial registration

ClinicalTrials.Gov, identifier NCT06349967.

Reversal of chemotherapy resistance in gastric cancer with traditional Chinese medicine as sensitizer: potential mechanism of action

Gastric cancer (GC) remains one of the most common types of cancer, ranking fifth among cancer-related deaths worldwide. Chemotherapy is an effective treatment for advanced GC. However, the development of chemotherapy resistance, which involves the malfunction of several signaling pathways and is the consequence of numerous variables interacting, seriously affects patient treatment and leads to poor clinical outcomes. Therefore, in order to treat GC, it is imperative to find novel medications that will increase chemotherapy sensitivity and reverse chemotherapy resistance. Traditional Chinese medicine (TCM) has been extensively researched as an adjuvant medication in recent years. It has been shown to have anticancer benefits and to be crucial in enhancing chemotherapy sensitivity and reducing chemotherapy resistance. Given this, the mechanism of treatment resistance in GC is summed up in this work. The theoretical foundation for TCM as a sensitizer in adjuvant treatment of GC is established by introducing the primary signal pathways and possible targets implicated in improving chemotherapy sensitivity and reversing chemotherapy resistance of GC by TCM and active ingredients.

Deep learning-based prediction of HER2 status and trastuzumab treatment efficacy of gastric adenocarcinoma based on morphological features

BACKGROUND

First-line treatment for advanced gastric adenocarcinoma (GAC) with human epidermal growth factor receptor 2 (HER2) is trastuzumab combined with chemotherapy. In clinical practice, HER2 positivity is identified through immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH), whereas deep learning (DL) can predict HER2 status based on tumor histopathological features. However, it remains uncertain whether these deep learning-derived features can predict the efficacy of anti-HER2 therapy.

METHODS

We analyzed a cohort of 300 consecutive surgical specimens and 101 biopsy specimens, all undergoing HER2 testing, along with 41 biopsy specimens receiving trastuzumab-based therapy for HER2-positive GAC.

RESULTS

We developed a convolutional neural network (CNN) model using surgical specimens that achieved an area under the curve (AUC) value of 0.847 in predicting HER2 amplification, and achieved an AUC of 0.903 in predicting HER2 status specifically in patients with HER2 2 + expression. The model also predicted HER2 status in gastric biopsy specimens, achieving an AUC of 0.723. Furthermore, our classifier was trained using 41 HER2-positive gastric biopsy specimens that had undergone trastuzumab treatment, our model demonstrated an AUC of 0.833 for the (CR + PR) / (SD + PD) subgroup.

CONCLUSION

This work explores an algorithm that utilizes hematoxylin and eosin (H&E) staining to accurately predict HER2 status and assess the response to trastuzumab in GAC, potentially facilitating clinical decision-making.

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.

Korean Practice Guidelines for Gastric Cancer 2024: An Evidence-based, Multidisciplinary Approach (Update of 2022 Guideline)

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area. Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version. Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

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.

Varlitinib and Paclitaxel for EGFR/HER2 Co-expressing Advanced Gastric Cancer: A Multicenter Phase Ib/II Study (K-MASTER-13)

PURPOSE

Varlitinib is a pan-human epidermal growth factor receptor (HER) inhibitor targeting epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and HER4. We present a phase Ib/II study of a combination of varlitinib and weekly paclitaxel as a second-line treatment for patients with EGFR/HER2 co-expressing advanced gastric cancer (AGC).

MATERIALS AND METHODS

Patients whose tumors with EGFR and HER2 overexpression by immunohistochemistry (≥ 1+) were enrolled. Varlitinib and paclitaxel were investigated every 4 weeks. After determining the recommended phase II dose (RP2D) in phase Ib, a phase II study was conducted to evaluate the antitumor activity.

RESULTS

RP2D was treated with a combination of varlitinib (300 mg twice daily) and paclitaxel. Among 27 patients treated with RP2D, the median progression-free survival and overall survival (OS) were 3.3 months (95% confidence interval [CI], 1.7 to 4.9) and 7.9 months (95% CI, 5.0 to 10.8), respectively, with a median follow-up of 15.7 months. Among 16 patients with measurable disease, the objective response rate (ORR) and disease control rate were 31% and 88%, respectively. Patients with strong HER2 expression (n=8) had a higher ORR and longer OS, whereas those with strong EGFR expression (n=3) had poorer outcomes. The most common adverse events (AEs) of any grade were neutropenia (52%), diarrhea (27%), aspartate aminotransferase/alanine transaminase elevation (22%), and nausea (19%). No treatment-related deaths or unexpected AEs resulting from treatment cessation were observed in patients with RP2D.

CONCLUSION

A combination of varlitinib and paclitaxel displayed manageable toxicity and modest antitumor activity in patients with EGFR/HER2 co-expressing AGC who progressed after first-line chemotherapy.

Unveiling promising targets in gastric cancer therapy: A comprehensive review

Gastric cancer (GC) poses a significant global health challenge, ranking fifth in incidence and third in mortality among all malignancies worldwide. Its insidious onset, aggressive growth, proclivity for metastasis, and limited treatment options have contributed to its high fatality rate. Traditional approaches for GC treatment primarily involve surgery and chemotherapy. However, there is growing interest in targeted therapies and immunotherapies. This comprehensive review highlights recent advancements in GC targeted therapy and immunotherapy. It delves into the mechanisms of various strategies, underscoring their potential in GC treatment. Additionally, the review evaluates the efficacy and safety of relevant clinical trials. Despite the benefits observed in numerous advanced GC patients with targeted therapies and immunotherapies, challenges persist. We discuss pertinent strategies to overcome these challenges, thereby providing a solid foundation for enhancing the clinical effectiveness of targeted therapies and immunotherapies.

Phase II Trial of HER-Vaxx, a B-cell Peptide-Based Vaccine, in HER2-Overexpressing Advanced Gastric Cancer Patients Under Platinum-Based Chemotherapy (HERIZON)

PURPOSE

A multicenter, randomized, open-label, phase II study (HERIZON; NCT02795988) was conducted to evaluate the clinical and immunologic efficacy of HER-Vaxx (IMU-131), a B-cell, peptide-based vaccine targeting HER2 overexpressed in 6% to 30% of gastroesophageal adenocarcinomas (GEA).

PATIENTS AND METHODS

Patients (n = 36) with GEA were treated with standard-of-care chemotherapy (n = 17) or HER-Vaxx plus chemotherapy (n = 19), using the recommended phase 2 dose for the vaccine. Overall survival (OS; primary endpoint), safety, progression-free survival (PFS), clinical response (secondary endpoints), and vaccine-induced HER2-specific antibody levels in serum and correlation with tumor response rates (exploratory endpoints) were investigated.

RESULTS

A 40% OS benefit [HR, 0.60; median OS, 13.9 months; 80% confidence interval (CI), 7.52-14.32] for patients treated with HER-Vaxx plus chemotherapy compared with OS of 8.31 months (80% CI, 6.01-9.59) in patients that received chemotherapy alone. A 20% PFS difference was obtained for the vaccination arm (HR, 0.80; 80% CI, 0.47, 1.38). No additional toxicity due to HER-Vaxx was observed. The vaccine-induced high levels of HER2-specific total IgG and IgG1 antibodies (P < 0.001 vs. controls) that significantly correlated with tumor reduction (IgG, P = 0.001; IgG1, P = 0.016), had a significant capacity in inhibiting phosphorylation of the intracellular HER2-signaling pathways, mediated antibody-dependent cellular cytotoxicity, and decreased immunosuppressive FOXP3+ regulatory T cells.

CONCLUSIONS

HER-Vaxx plus standard chemotherapy exhibits an excellent safety profile and improves OS. Furthermore, vaccine-induced immune response was significantly associated with reduced tumor size compared with standard-of-care chemotherapy. The presented vaccination approach may substitute for treatment with trastuzumab, upon unavailability or toxicity, based on further evidence of equivalent treatment efficacy.

HER2-low gastric cancer: is the subgroup targetable?

Therapeutic developments in the targeting of human epidermal growth factor receptor 2 (HER2)-expressing gastric cancer have followed the dramatic success of HER2-expressing breast cancer treatment, which has facilitated the expansion of indications for anti-HER2 agents to include not only conventional HER2-positive breast cancer, but also HER2-low and HER2-ultralow subgroups. The targetability of HER2-low gastric cancer, however, has yet to be established. Hence, further studies are needed to comprehensively understand the clinicopathological features, specific gene alterations, and distinct tumor immune microenvironment of HER2-low gastric cancer and compare them with those for HER2-positive or -negative gastric cancer. Antibody-drug conjugates for HER2 play an important role in making HER2-low gastric cancer targetable. In this context, a deeper understanding of the novel anti-HER2 agents, including antibody-drug conjugates, bispecific T-cell engager antibodies, and a combination of these agents, as well as new forms of immunomodulatory agents are also required. Redefining and re-categorizing HER2 status through not only immunohistochemistry/fluorescence in situ hybridization but also evaluating ERRB2 copy number gain or protein overexpression levels measured using DNA or RNA sequencing might be helpful for identifying populations with HER2-expressing tumors who would ideally benefit from anti-HER2 treatment. The current paper reviewed recent clinical trials, focusing particularly on HER2-low gastric cancer together with basic/translational findings, and discuss perspectives on further therapeutic development in the treatment of this distinct subgroup.

Clinical outcomes and ctDNA correlates for CAPOX BETR: a phase II trial of capecitabine, oxaliplatin, bevacizumab, trastuzumab in previously untreated advanced HER2+ gastroesophageal adenocarcinoma

Preclinical studies suggest that simultaneous HER2/VEGF blockade may have cooperative effects in gastroesophageal adenocarcinomas. In a single-arm investigator initiated clinical trial for patients with untreated advanced HER2+ gastroesophageal adenocarcinoma, bevacizumab was added to standard of care capecitabine, oxaliplatin, and trastuzumab in 36 patients (NCT01191697). Primary endpoint was objective response rate and secondary endpoints included safety, duration of response, progression free survival, and overall survival. The study met its primary endpoint with an objective response rate of 81% (95% CI 65-92%). Median progression free and overall survival were 14.0 (95% CI, 11.3-36.4) and 23.2 months (95% CI, 16.6-36.4), respectively. The median duration of response was 14.9 months. The regimen was well tolerated without unexpected or severe toxicities. In post-hoc ctDNA analysis, baseline ctDNA features were prognostic: Higher tumor fraction and alternative MAPK drivers portended worse outcomes. ctDNA at resistance identified oncogenic mutations and these were detectable 2-8 cycles prior to radiographic progression. Capecitabine, oxaliplatin, trastuzumab and bevacizumab shows robust clinical activity in HER2+ gastroesophageal adenocarcinoma. Combination of VEGF inhibitors with chemoimmunotherapy and anti-PD1 regimens is warranted.

Prediction of HER2 Expression in Gastric Adenocarcinoma Based On Preoperative Noninvasive Multimodal 18F-FDG PET/CT Imaging

RATIONALE AND OBJECTIVES

This study aims to investigate the role of a flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) multimodal radiomics model in predicting the status of human epidermal growth factor receptor 2 (HER2) expression preoperatively in cases of gastric adenocarcinoma.

MATERIALS AND METHODS

This retrospective study included 133 patients with gastric adenocarcinoma who were classified into training (n = 93) and validation (n = 40) cohorts in a ratio of 7:3. Features were selected using Least Absolute Shrinkage and Selection Operator and Extreme Gradient Boosting (XGBoost) methods; further, prediction models were constructed using logistic regression and XGBoost. These models were evaluated and validated using area under the curve (AUC), decision curves, and calibration curves to select the best-performing model.

RESULTS

Six different models were established to predict HER2 expression. Among these, the comprehensive model, which integrates seven clinical features, one CT feature, and five PET features, demonstrated AUC values of 0.95 (95% confidence interval [CI]: 0.89-1.00) and 0.76 (95% CI: 0.52-1.00) in the training and validation cohorts, respectively. Compared with other models, this model exhibited a superior net benefit on the decision curve and demonstrated good alignment agreement with the observed values on the calibration curve. Based on these findings, we constructed a nomogram for visualizing the model, providing a noninvasive preoperative method for predicting HER2 expression.

CONCLUSION

The preoperative 18F-FDG PET/CT multimodal radiomics model can effectively predict HER2 expression in patients with gastric adenocarcinoma, thereby guiding clinical decision-making and advancing the field of precision medicine.

Pembrolizumab in combination with trastuzumab for treatment of HER2-positive advanced gastric or gastro-esophageal junction cancer

Introduction

Gastric cancer remains a challenging malignancy with a high global mortality rate. Recent advances in targeted therapy and immunotherapy have shown promise in improving patient outcomes. This paper reviews the impact of incorporating targeted agents such as trastuzumab and immunotherapeutic agents like pembrolizumab into standard chemotherapy regimens for gastric cancer treatment.

Methods

A comprehensive analysis was conducted on pivotal clinical trials, including KEYNOTE-590, KEYNOTE-811, and ToGA, focusing on their methodologies, patient populations, treatment regimens, and outcome measures. The review also explored emerging research avenues in precision medicine, particularly genomic sequencing and biomarker identification.

Aim

To assess the efficacy and survival benefits of adding trastuzumab and pembrolizumab to standard chemotherapy in the treatment of gastric cancer and to outline future directions in gastric cancer research.

Results

Including trastuzumab and pembrolizumab in treatment regimens for human epidermal growth factor receptor 2 (HER2)-positive and PD-L1-expressing gastric cancers significantly improved progression-free and overall survival rates compared to chemotherapy alone. These findings highlight the potential of personalized therapy in enhancing treatment outcomes. Furthermore, ongoing research into the gastric cancer microenvironment and the role of the microbiome suggests novel targets for future therapeutic interventions.

Conclusion

The integration of targeted and immunotherapeutic agents with traditional chemotherapy represents a pivotal shift in gastric cancer treatment, moving towards more personalized and effective regimens.

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.

High Expression of CLDN 18.2 is Associated with Poor Disease-Free Survival of HER-2 Positive Gastric Cancer

Background

Anti-claudin (CLDN) 18.2 therapy has been proven to be effective in treating advanced gastric cancer with negative human epidermal growth factor receptor 2 (HER-2). This study purposed to investigate the relationship of CLDN 18.2 expression with prognosis of HER-2-positive gastric cancer patients.

Objective

To investigate the expression of claudin (CLDN) 18.2 in Human epidermal growth factor receptor 2 (HER-2) positive gastric cancer patients after radical resection and its relationship with gastric cancer prognosis.

Methods

A total of 55 postoperative HER-2-positive gastric cancer patients were included in this study. CLDN 18.2 protein was detected by immunohistochemistry, and detailed clinical and pathological information was collected. Factors considered potentially important in the univariate analysis were included in the multivariate analysis, which involved COX regression to find the independent prognostic factors affecting disease-free survival (DFS).

Results

Immunohistochemistry showed that different levels of CLDN 18.2 protein were expressed in HER-2 positive gastric cancer tissues, and the Chi-square analysis showed that the expression level of CLDN 18.2 was significantly correlated with the lymph node stage. Higher expression levels of CLDN 18.2 were found in patients with lymph node positivity and were associated with poor prognosis in HER-2-positive gastric cancer patients. Gastric cancer patients with low and high expressions of CLDN 18.2 had postoperative median DFS of 38.5 months (95% confidence interval (CI) 28.8-48.2 months) and 12.1 months (95% CI, 11.7-41.0 months), respectively.

Conclusion

High expression of CLDN 18.2 in HER-2 positive gastric cancer is associated with poor prognosis, and the optimal treatment mode for this population is worth exploring after the approval of anti-CLDN 18.2 drugs.

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.

HER2-Positive Gastric Cancer and Antibody Treatment: State of the Art and Future Developments

Despite a decreasing incidence in Western countries, gastric cancer is among the most common cancer subtypes globally and is associated with one of the highest tumor-related mortality rates. Biomarkers play an increasing role in the treatment against gastric cancer. HER2 was one of the first biomarkers that found its way into clinical practice. Since the ToGA trial, trastuzumab has been part of first-line palliative chemotherapy in metastatic or unresectable gastric cancer. HER2-targeting agents, such as the tyrosine kinase inhibitor lapatinib, the antibody drug conjugate (ADC) trastuzumab-emtansine or dual HER2 inhibition (pertuzumab and trastuzumab), have been investigated in the second-line setting but led to negative study results. More recently, the ADC trastuzumab-deruxtecan was authorized after the failure of trastuzumab-based treatment. However, further improvements in HER2-directed therapy are required as resistance mechanisms and HER2 heterogeneity limit the existing treatment options. This review aims to give an overview of the current standard-of-care HER2-directed therapy in gastric cancer, as well as its challenges and future developments.

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.