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.

Multiple primary malignant tumors refer to the occurrence of two or more primary malignant tumors in the same organ or multiple organs or tissues at the same time or successively in the same patient, and can occur anywhere in the body. The treatment guidelines for patients with multiple primary malignant tumors are currently controversial.

A 51-year-old male patient with liver cancer and portal hypertension received 42 months of co-treatment with atezolizumab and bevacizumab. After that, the disease was rated stable disease. The patient was then diagnosed with gastric cancer. Since the patient was not sensitive to anti-programmed death ligand 1 immunosuppressive agents, a co-treatment with oxaliplatin, tegafur, apatinib, and cadonilimab was selected after multidisciplinary consultation and the patient's agreement. After four cycles of treatment, partial response and stable disease were observed in gastric and liver cancers, respectively. Surgical treatment was performed considering the high-risk factors of gastrointestinal bleeding in patients with gastroesophageal varices. Postoperative pathology showed that the Tumor Regression Grade was 1. Moreover, the genetic testing of postoperative tumor specimens indicated negative programmed death ligand 1 and microsatellite stability. In addition, the latest follow-up indicated an 8 and 40-month progression-free survival in gastric and liver cancer patients, respectively. Currently, the patient is receiving postoperative immunotherapy with cadonilimab.

Cadonilimab not only treats microsatellite stability gastric cancer patients but can also be used for liver cancer treatment.

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, with limited treatment options in advanced stages. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) targeting PD1/PD-L1, has emerged as a promising therapeutic approach. However, a significant proportion of patients exhibit primary or acquired resistance, limiting the overall efficacy of immunotherapy. This review provides a comprehensive analysis of the mechanisms underlying immunotherapy resistance in GC, including the role of the tumor immune microenvironment, dynamic PD-L1 expression, compensatory activation of other immune checkpoints, and tumor genomic instability. Furthermore, the review explores GC-specific factors such as molecular subtypes, unique immune evasion mechanisms, and the impact of Helicobacter pylori infection. We also discuss emerging strategies to overcome resistance, including combination therapies, novel immunotherapeutic approaches, and personalized treatment strategies based on tumor genomics and the immune microenvironment. By highlighting these key areas, this review aims to inform future research directions and clinical practice, ultimately improving outcomes for GC patients undergoing immunotherapy.

The outcome of patients with recurrent/metastatic cervical cancer (R/M CC) is poor, with a 5-year survival rate of only 10%-20%. Recent advances in immunotherapy renewed its interest in R/M CC treatment. It has been suggested that cadonilimab, a novel bispecific antibody targeting programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4), significantly improved the survival outcomes of the R/M CC. In the present study, we reported a programmed death ligand 1 (PD-L1) and human epidermal growth factor receptor 2 (HER-2) positive CC case at stage IV who was treated with cadonilimab and achieved a surprising radiographic complete response (CR) for 10 months, even in the PD-L1 negative metastatic site. Demographic, clinical, histopathological, laboratory, treatment regime and imaging data were recorded. Unfortunately, the patient progressed rapidly during maintenance therapy when cadonilimab was replaced by sintilimab, the monoclonal antibody against PD-1, indicating the more powerful anti-tumor activity of dual blockade immunotherapy. To conclude, cadonilimab offers a promising and effective therapeutic approach for R/M CC. Notably, HER-2 is also expected to be a new reference target for cadonilimab therapy.

Targeting immune receptors on T cells is a common strategy to treat cancer and autoimmunity. Frequently, this is accomplished through monoclonal antibodies targeting the ligand binding sites of stimulatory or inhibitory co-receptors. Blocking ligand binding prevents downstream signalling and modulates specific T cell functions. Since 1985, the FDA has approved over 100 monoclonal antibodies against immune receptors. This therapeutic approach significantly improved the care of patients with numerous immune-related conditions; however, many patients are unresponsive, and some develop immune-related adverse events. One reason for that is the lack of consideration for the localization of these receptors on the cell surface of the immune cells in the context of the immune synapse. In addition to blocking ligand binding, changing the location of these receptors on the cell surface within the different compartments of the immunological synapse could serve as an alternative, efficient, and safer approach to treating these patients. This review discusses the potential therapeutic advantages of altering proteins' localization within the immune synapse and summarizes published work in this field. It also discusses the novel use of bispecific antibodies to induce the clustering of receptors on the cell surface. It presents the rationale for developing novel antibodies, targeting the organization of signalling receptor complexes on the cell surface. This approach offers an innovative and emerging technology to treat cancer patients resistant to current immunotherapies.

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.

Gastric cancer remains a considerable global health burden, with limited treatment options available for advanced cases, especially for superaged patients. Cadonilimab, a first-in-class bi-specific antibody (BsAb), offer a promising immunotherapy approach by targeting PD-1/CTLA-4 simultaneously. Herein, we present a case report of an 85-year-old patient with HER2-negative advanced gastric cancer who received first-line treatment with cadonilimab combined with chemotherapy, but cadonilimab was discontinued due to the observation of immune-related pneumonitis during treatment. Despite these changes, the patient still exhibited a stable disease condition for a year until now. This case report highlights the potential of cadonilimab in the treatment of superaged patients with advanced gastric cancer, while the efficacy and safety of it need to be further evaluated.

In this editorial, we comment on the article "Analysis of the impact of immunotherapy efficacy and safety in patients with gastric cancer and liver metastasis" by Liu et al that was published in the recent issue of the World Journal of Gastrointestinal Surgery. It has prompted us to think and summarize some thoughts on immunotherapy for malignant tumor liver metastasis. Immunotherapy plays a crucial role in the treatment of malignant tumors; however, the presence of liver metastases in advanced tumors may impact its efficacy. Although patients with liver metastases can still benefit from immunotherapy, multiple clinical studies have indicated that, compared to other sites of metastasis, liver metastases may diminish the effectiveness of immunotherapy. The efficacy of immune checkpoint inhibitors in patients with liver metastases often fails to reach the ideal level, primarily due to the liver metastases exploiting the host's peripheral immune tolerance mechanisms to promote systemic CD8(+) T cell exhaustion, resulting in a systemic immune-tolerant environment. This article aims to summarize the reasons for the decreased efficacy of immunotherapy following liver metastasis in various malignant tumors and propose potential clinical strategies for management.

The lack of an efficient way to screen patients who are responsive to immunotherapy challenges PD1/CTLA4-targeting cancer treatment. Immunotherapeutic efficacy cannot be clearly determined by peripheral blood analyses, tissue gene markers or CT/MR value. Here, we used a radionuclide and imaging techniques to investigate the novel dual targeted antibody cadonilimab (AK104) in PD1/CTLA4-positive cells in vivo.

First, humanized PD1/CTLA4 mice were purchased from Biocytogen Pharmaceuticals (Beijing) Co., Ltd. to express hPD1/CTLA4 in T-cells. Then, mouse colon cancer MC38-hPD-L1 cell xenografts were established in humanized mice. A bispecific antibody targeting PD1/CTLA4 (AK104) was labeled with radio-nuclide iodine isotopes. Immuno-PET/CT imaging was performed using a bispecific monoclonal antibody (mAb) probe 124I-AK104, developed in-house, to locate PD1+/CTLA4+ tumor-infiltrating T cells and monitor their distribution in mice to evaluate the therapeutic effect.

The 124I-AK104 dual-antibody was successfully constructed with ideal radiochemical characteristics, in vitro stability and specificity. The results of immuno-PET showed that 124I-AK104 revealed strong hPD1/CTLA4-positive responses with high specificity in humanized mice. High uptake of 124I-AK104 was observed not only at the tumor site but also in the spleen. Compared with PD1- or CTLA4-targeting mAb imaging, 124I-AK104 imaging had excellent standard uptake values at the tumor site and higher tumor to nontumor (T/NT) ratios.

The results demonstrated the potential of translating 124I-AK104 into a method for screening patients who benefit from immunotherapy and the efficacy, as well as the feasibility, of this method was verified by immuno-PET imaging of humanized mice.

PD-1/PD-L1 blockade therapy has brought great success to cancer treatment. Nevertheless, limited beneficiary populations and even hyperprogressive disease (HPD) greatly constrain the application of PD-1/PD-L1 inhibitors in clinical treatment. HPD is a special pattern of disease progression with rapid tumor growth and even serious consequences of patient death, which requires urgent attention. Among the many predisposing causes of HPD, regulatory T cells (Tregs) are suspected because they are amplified in cases of HPD. Tregs express PD-1 thus PD-1/PD-L1 blockade therapy may have an impact on Tregs which leads to HPD. Tregs are a subset of CD4+ T cells expressing FoxP3 and play critical roles in suppressing immunity. Tregs migrate toward tumors in the presence of chemokines to suppress antitumor immune responses, causing cancer cells to grow and proliferate. Studies have shown that deleting Tregs could enhance the efficacy of PD-1/PD-L1 blockade therapy and reduce the occurrence of HPD. This suggests that immunotherapy combined with Treg depletion may be an effective means of avoiding HPD. In this review, we summarized the immunosuppressive-related functions of Tregs in antitumor therapy and focused on advances in therapy combining Tregs depletion with PD-1/PD-L1 blockade in clinical studies. Moreover, we provided an outlook on Treg-targeted HPD early warning for PD-1/PD-L1 blockade therapy.

The prognosis for patients with advanced metastatic cervix cancer (MCC) is poor, and this disease continues to pose a considerable therapeutic challenge. Despite the administration of first-line regimens consisting of cisplatin, paclitaxel, and bevacizumab, survival rates for patients with metastasis remain poor. The emergence of bispecific antibodies (BsAbs) offers a novel treatment option for patients diagnosed with MCC.

In this report, we present a patient with MCC who was treated with cadonilimab monotherapy at a dose of 6 mg/kg every two weeks after chemotherapy was proven to be intolerable. The patient exhibited a sustained complete response for a duration of 6 months, demonstrating an optimistic outlook.

This case illustrates the considerable efficacy of cadonilimab for treating advanced MCC. Therefore, BsAb therapy is a promising strategy for effectively treating patients with advanced MCC and should be considered as an option when patients are intolerant to standard chemotherapy.

Advanced hepatocellular carcinoma (HCC) is a severe malignancy that poses a serious threat to human health. Owing to challenges in early diagnosis, most patients lose the opportunity for radical treatment when diagnosed. Nonetheless, recent advancements in cancer immunotherapy provide new directions for the treatment of HCC. For instance, monoclonal antibodies against immune checkpoint inhibitors (ICIs) such as programmed cell death protein 1/death ligand-1 inhibitors and cytotoxic t-lymphocyte associated antigen-4 significantly improved the prognosis of patients with HCC. However, tumor cells can evade the immune system through various mechanisms. With the rapid development of genetic engineering and molecular biology, various new immunotherapies have been used to treat HCC, including ICIs, chimeric antigen receptor T cells, engineered cytokines, and certain cancer vaccines. This review summarizes the current status, research progress, and future directions of different immunotherapy strategies in the treatment of HCC.