Immunotherapy for oesophagogastric cancer

Treatment- and immune-related adverse events of immune checkpoint inhibitors in esophageal or gastroesophageal junction cancer: A network meta-analysis of randomized controlled trials

Objective

To systematically evaluate the safety and adverse event profiles of immune checkpoint inhibitors (ICIs) in patients with esophageal cancer (EPC) or gastroesophageal junction cancer (GEJC).

Methods

PubMed, Web of Science, Cochrane Library, and major conference proceedings were systematically searched for all phase II or phase III randomized controlled trials (RCTs) in EPC or GEJC using ICIs. Safety outcomes including treatment-related adverse events (trAEs), immune-related adverse events (irAEs), and serious trAEs were evaluated by network meta-analysis or dichotomous meta-analysis based on the random-effects model.

Results

Eleven RCTs involving EPC (five RCTs) and GEJC (six RCTs) were included in the final meta-analysis. NMA showed that placebo was associated with the best safety ranking for grade 3-5 trAEs (SUCRA = 96.0%), followed by avelumab (78.6%), nivolumab (73.9%), ipilimumab (57.0%), and pembrolizumab (56.6%). Conventional pairwise meta-analysis (CPM) showed that ICIs have similar grade 3-5 trAE risk compared with chemotherapy (RR = 0.764, 95% CI: 0.574 to 1.016, I ² = 95.7%, Z = 1.85, P = 0.065). NMA showed that the general safety of grade 3-5 irAEs ranked from high to low is as follows: ChT (85.1%), placebo (76.5%), ipilimumab (56.0%), nivolumab (48.5%), avelumab (48.4%), camrelizumab (41.8%), pembrolizumab (36.4%), and nivolumab + ipilimumab (21.6%). CPM showed that the rates of grade 3-5 irAEs in the ICI group and the chemotherapy group were 7.35% (154/2,095, 95% CI: [6.23%, 8.47%]) versus 2.25% (42/1,869, 95% CI: [1.58%, 2.92%]), with statistical significance (RR = 3.151, 95% CI = 2.175 to 4.563, Z = 6.07, P = 0.000). The most common irAEs in the ICI group were skin reaction (15.76%, 95% CI: [13.67%, 17.84%]), followed by hypothyroidism (9.73%, 95% CI: [8.07%, 11.39%]), infusion-related reactions (5.93%, 95% CI: [4.29%, 7.58%]), hepatitis (5.25%, 95% CI: [4.28%, 6.22%]), and pneumonitis (4.45%, 95% CI: [3.5%, 5.4%]).

Conclusion

Different ICIs had different toxicity manifestations and should not be considered as an entity. Compared with chemotherapy, ICIs were more prone to irAEs, but the overall rates remained low and acceptable. For clinicians, it is important to recognize and monitor the adverse events caused by ICIs for patients with EPC or GEJC.

Neoantigens and their clinical applications in human gastrointestinal cancers

Background

Tumor-specific neoantigens are ideal targets for cancer immunotherapy. As research findings have proved, neoantigen-specific T cell activity is immunotherapy’s most important determinant.

Main text

There is sufficient evidence showing the role of neoantigens in clinically successful immunotherapy, providing a justification for targeting. Because of the significance of the pre-existing anti-tumor immune response for the immune checkpoint inhibitor, it is believed that personalized neoantigen-based therapy may be an imperative approach for cancer therapy. Thus, intensive attention is given to strategies targeting neoantigens for the significant impact with other immunotherapies, such as the immune checkpoint inhibitor. Today, several algorithms are designed and optimized based on Next-Generation Sequencing and public databases, including dbPepNeo, TANTIGEN 2.0, Cancer Antigenic Peptide Database, NEPdb, and CEDAR databases for predicting neoantigens in silico that stimulates the development of T cell therapies, cancer vaccine, and other ongoing immunotherapy approaches.

Conclusions

In this review, we deliberated the current developments in understanding and recognition of the immunogenicity of newly found gastrointestinal neoantigens as well as their functions in immunotherapies and cancer detection. We also described how neoantigens are being developed and how they might be used in the treatment of GI malignancies.

The Clinical Application of Neoantigens in Esophageal Cancer

Esophageal cancer (EC) is a common malignant tumor with poor prognosis, and current treatments for patients with advanced EC remain unsatisfactory. Recently, immunotherapy has been recognized as a new and promising approach for various tumors. EC cells present a high tumor mutation burden and harbor abundant tumor antigens, including tumor-associated antigens and tumor-specific antigens. The latter, also referred to as neoantigens, are immunogenic mutated peptides presented by major histocompatibility complex class I molecules. While current genomics and bioinformatics technologies have greatly facilitated the identification of tumor neoantigens, identifying individual neoantigens systematically for successful therapies remains a challenging problem. Owing to the initiation of strong, specific tumor-killing cytotoxic T cell responses, neoantigens are emerging as promising targets to develop personalized treatment and have triggered the development of cancer vaccines, adoptive T cell therapies, and combination therapies. This review aims to give a current understanding of the clinical application of neoantigens in EC and provide direction for future investigation.

Immunotherapy in gastroesophageal cancers: Current state and future directions

While gastroesophageal (GE) cancers are one of the most common cancers worldwide, unfortunately, the mortality remains high. Commonly used treatment options include surgical resection, chemotherapy, radiotherapy, and molecular targeted therapy, which improve survival only minimally; thus, affirming the dire need for exploring alternative strategies to improve patient outcomes. Immunotherapy, which has revolutionized the world of oncology, has somewhat lagged behind in GE malignancies. Tumor-associated microenvironment and regulatory T cells, alongside cell cycle checkpoints, have been proposed by various studies as the mediators of carcinogenesis in GE cancers. Thus, inhibition of each of these could serve as a possible target of treatment. While the approval of pembrolizumab has provided some hope, it is not enough to override the dismal prognosis that this disease confers. Herein, we discuss the prospects of immunotherapy in this variety of cancer.

Synergism Between Immunotherapy and Radiotherapy in Esophageal Cancer: An Overview of Current Knowledge and Future Perspectives

Background: Esophageal cancer (EC) is an aggressive neoplasm of the gastrointestinal tract that is usually treated with a combination of chemotherapy, radiotherapy (RT), and/or surgery, according to disease status. Despite the availability of multimodal therapeutic strategies, local recurrence is frequently observed. Immunotherapy is a promising therapeutic approach that is currently highly investigated in association to standard therapies, including RT, with the aim to improve patients' outcomes. Materials and Methods: A PubMed search was performed with the following keywords in all fields: "esophageal cancer" and "radiotherapy" and "radiation" and "immunotherapy" and "PD-1" and "PD L1." For an overview of ongoing trials, an additional search on ClinicalTrials.gov website was performed using the keywords "esophageal cancer" and "immunotherapy" and "PD-L1" and "CTLA-4" and "radiation" and "radiotherapy." Emerging data from preclinical and clinical studies are suggesting a synergistic effect between immunotherapy and RT. With the aim to update the knowledge of this synergistic immune-mediated antitumor activity and discuss current challenges, the authors summarize published data concerning the basic mechanisms and the effectiveness and tolerance of the combination between immunotherapy and RT for patients with EC, followed by an overview of ongoing clinical trial. Conclusions: Published results encourage the use of personalized therapeutic approaches for EC patients in the future; results from ongoing studies will help to identify the optimal strategies for patient selection and treatment response evaluation.