Effects of immune-related adverse events (irAEs) and their treatment on antitumor immune responses

New insights into immune cells in cancer immunotherapy: from epigenetic modification, metabolic modulation to cell communication

Cancer is one of the leading causes of death worldwide, and more effective ways of attacking cancer are being sought. Cancer immunotherapy is a new and effective therapeutic method after surgery, radiotherapy, chemotherapy, and targeted therapy. Cancer immunotherapy aims to kill tumor cells by stimulating or rebuilding the body's immune system, with specific efficiency and high safety. However, only few tumor patients respond to immunotherapy and due to the complex and variable characters of cancer immune escape, the behavior and regulatory mechanisms of immune cells need to be deeply explored from more dimensions. Epigenetic modifications, metabolic modulation, and cell-to-cell communication are key factors in immune cell adaptation and response to the complex tumor microenvironment. They collectively determine the state and function of immune cells through modulating gene expression, changing in energy and nutrient demands. In addition, immune cells engage in complex communication networks with other immune components, which are mediated by exosomes, cytokines, and chemokines, and are pivotal in shaping the tumor progression and therapeutic response. Understanding the interactions and combined effects of such multidimensions mechanisms in immune cell modulation is important for revealing the mechanisms of immunotherapy failure and developing new therapeutic targets and strategies.

The opportunities and challenges of using PD-1/PD-L1 inhibitors for leukemia treatment

Leukemia poses a significant clinical challenge due to its swift onset, rapid progression, and treatment-related complications. Tumor immune evasion, facilitated by immune checkpoints like programmed death receptor 1/programmed death receptor ligand 1 (PD-1/PD-L1), plays a critical role in leukemia pathogenesis and progression. In this review, we summarized the research progress and therapeutic potential of PD-L1 in leukemia, focusing on targeted therapy and immunotherapy. Recent clinical trials have demonstrated promising outcomes with PD-L1 inhibitors, highlighting their role in enhancing treatment efficacy. This review discusses the implications of PD-L1 expression levels on treatment response and long-term survival rates in leukemia patients. Furthermore, we address the challenges and opportunities in immunotherapy, emphasizing the need for personalized approaches and combination therapies to optimize PD-L1 inhibition in leukemia management. Future research prospects include exploring novel treatment strategies and addressing immune-related adverse events to improve clinical outcomes in leukemia. Overall, this review provides valuable insights into the role of PD-L1 in leukemia and its potential as a therapeutic target in the evolving landscape of leukemia treatment.

Inhibition of IL-25/IL-17RA improves immune-related adverse events of checkpoint inhibitors and reveals antitumor activity

BACKGROUND

Immune checkpoint inhibitors (ICIs) have improved outcomes and extended patient survival in several tumor types. However, ICIs often induce immune-related adverse events (irAEs) that warrant therapy cessation, thereby limiting the overall effectiveness of this class of therapeutic agents. Currently, available therapies used to treat irAEs might also blunt the antitumor activity of the ICI themselves. Therefore, there is an urgent need to identify treatments that have the potential to be administered alongside ICI to optimize their use.

METHODS

Using a translationally relevant murine model of anti-PD-1 and anti-CTLA-4 antibodies-induced irAEs, we compared the safety and efficacy of prednisolone, anti-IL-6, anti-TNFɑ, anti-IL-25 (IL-17E), and anti-IL-17RA (the receptor for IL-25) administration to prevent irAEs and to reduce tumor size.

RESULTS

While all interventions were adequate to inhibit the onset of irAEs pneumonitis and hepatitis, treatment with anti-IL-25 or anti-IL-17RA antibodies also exerted additional antitumor activity. Mechanistically, IL-25/IL-17RA blockade reduced the number of organ-infiltrating lymphocytes.

CONCLUSION

These findings suggest that IL-25/IL-17RA may serve as an additional target when treating ICI-responsive tumors, allowing for better tumor control while suppressing immune-related toxicities.

Precision treatment in advanced hepatocellular carcinoma

The past decade has witnessed significant advances in the systemic treatment of advanced hepatocellular carcinoma (HCC). Nevertheless, the newly developed treatment strategies have not achieved universal success and HCC patients frequently exhibit therapeutic resistance to these therapies. Precision treatment represents a paradigm shift in cancer treatment in recent years. This approach utilizes the unique molecular characteristics of individual patient to personalize treatment modalities, aiming to maximize therapeutic efficacy while minimizing side effects. Although precision treatment has shown significant success in multiple cancer types, its application in HCC remains in its infancy. In this review, we discuss key aspects of precision treatment in HCC, including therapeutic biomarkers, molecular classifications, and the heterogeneity of the tumor microenvironment. We also propose future directions, ranging from revolutionizing current treatment methodologies to personalizing therapy through functional assays, which will accelerate the next phase of advancements in this area.

Gut microbiome for predicting immune checkpoint blockade-associated adverse events

BACKGROUND

The impact of the gut microbiome on the initiation and intensity of immune-related adverse events (irAEs) prompted by immune checkpoint inhibitors (ICIs) is widely acknowledged. Nevertheless, there is inconsistency in the gut microbial associations with irAEs reported across various studies.

METHODS

We performed a comprehensive analysis leveraging a dataset that included published microbiome data (n = 317) and in-house generated data from 16S rRNA and shotgun metagenome samples of irAEs (n = 115). We utilized a machine learning-based approach, specifically the Random Forest (RF) algorithm, to construct a microbiome-based classifier capable of distinguishing between non-irAEs and irAEs. Additionally, we conducted a comprehensive analysis, integrating transcriptome and metagenome profiling, to explore potential underlying mechanisms.

RESULTS

We identified specific microbial species capable of distinguishing between patients experiencing irAEs and non-irAEs. The RF classifier, developed using 14 microbial features, demonstrated robust discriminatory power between non-irAEs and irAEs (AUC = 0.88). Moreover, the predictive score from our classifier exhibited significant discriminative capability for identifying non-irAEs in two independent cohorts. Our functional analysis revealed that the altered microbiome in non-irAEs was characterized by an increased menaquinone biosynthesis, accompanied by elevated expression of rate-limiting enzymes menH and menC. Targeted metabolomics analysis further highlighted a notably higher abundance of menaquinone in the serum of patients who did not develop irAEs compared to the irAEs group.

CONCLUSIONS

Our study underscores the potential of microbial biomarkers for predicting the onset of irAEs and highlights menaquinone, a metabolite derived from the microbiome community, as a possible selective therapeutic agent for modulating the occurrence of irAEs.

Experience of patients considering or using checkpoint inhibitors in cancer treatment: a systematic review of qualitative research

Increasing numbers of patients with cancer are considering or undergoing immunotherapy, however, little is known about patients' perspectives on this treatment. We undertook a systematic review for use by clinicians and researchers, consolidating published qualitative research studies on patient experience of checkpoint inhibitor therapy. A search of Medline, Embase, and PsycINFO was carried out for publications in English to 30 June 2022. Publications were selected if they reported a qualitative study of patient experience with checkpoint inhibitor therapy for cancer, either by patients or their families or carers. Quality was appraised using the Johanna Briggs Institute quality assessment tool for qualitative studies. A thematic synthesis was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard was followed. We identified 17 eligible studies published between 2017 and 2022, 9 using mixed methods, and 8 solely using qualitative methods. Most studies reported on the experiences of patients with advanced stage melanoma and were using the earliest approved checkpoint inhibitors for cancer therapy. Studies met most formal quality criteria but varied in the extent of their qualitative explorations of data; some mixed methods studies had limited reporting of qualitative results. Through thematic synthesis, we categorized study findings into four domains: (1) treatment decision-making; (2) success with immunotherapy; (3) treatment-related adverse events (AEs); and (4) quality of life on immunotherapy. Our review identified several areas with potential for improving the care system. These include, for example: routinely linking patients to peers who have experienced this therapy; improving the capacity of patients and carers to identify and report AEs faster; and supporting patients and carers to live with changed circumstances after successful treatment. Most studies focused on patients who had successful treatment, effectively excluding those who do not respond or who discontinue due to serious side effects; future research targets are suggested.

Tolerated Re-Challenge of Immunotherapy in a Patient with ICI Associated Myocarditis: A Case Report and Literature Review

Many different types of cancer can be treated with immunotherapy drugs called immune checkpoint inhibitors (ICIs). These drugs have altered the landscape of cancer treatment options since they function by triggering a stronger immune response to malignancy. As expected, ICIs' modification of immune regulatory controls leads to a wide range of organ/gland-specific immune-related side effects. These adverse effects are uncommonly deadly and typically improve by discontinuing treatment or administering corticosteroid drugs. As a result of a number of factors-including a lack of specificity in the clinical presentation, the possibility of overlap with other cardiovascular and general medical illnesses, difficulties in diagnosis, and a general lack of awareness-the true incidence of ICI-associated myocarditis is likely underestimated. Currently, protocols for the surveillance, diagnosis, or treatment of this condition are unclear. Several questions remain unanswered, such as how to best screen for this rare toxin, what tests should be run on patients who are suspected of having it, how to treat myocarditis once it has developed, and who is at most risk. In this article, we provide a case study of ICI-associated myocarditis and explain its key characteristics and treatment options.