scholarly journals Understanding Checkpoint Inhibitors in Cancer Therapy, Mechanisms of Action, Resistance and Future Challenges

2020 ◽  
pp. 1-13
Author(s):  
Harman Saman ◽  
Harman Saman ◽  
Shahab Uddin ◽  
Syed Raza ◽  
Raj Shrimali ◽  
...  

The immune system is the human body’s natural defence against mutated cells produced as the result of DNA replicative error or by the effect of carcinogens, a process rereferred to as immune surveillance. ‘Escaping’ of cancer cells from immune surveillance leads to tumor development, metastasis and progression. Avoiding detection and destruction by the immune system are the result of cancer cells evolution, caused primarily by cancer cells’ genomic instability. On the other hand, scientists attempted for decades to exploit the anticancer effect of the immune system with limited success. However, better understanding of the mechanisms behind the cancer cells’ ability to avoid detection and suppression by the immune system resulted in the development of immune checkpoint inhibitors, a form of immunotherapy, first approved by the Food and Drug Administration (FDA) in 2011. This article reviews the pathways involved in anticancer immune response, evading and supressing of the immune system by cancer cells mechanisms of action and successes of immune checkpoint inhibitors (ICI), particularly programmed death1 (PD-1) and programmed death-ligand (PD-L1) inhibitors as well as mechanisms that result in resistance of cancer cells to ICI.

2021 ◽  
Vol 12 ◽  
Author(s):  
Pan Shen ◽  
Liang Han ◽  
Xin Ba ◽  
Kai Qin ◽  
Shenghao Tu

Immunotherapy, which takes advantage of the immune system to eliminate cancer cells, has been widely studied and applied in oncology. Immune checkpoint inhibitors (ICIs) prevent the immune system from being turned off before cancer cells are eliminated. They have proven to be among the most promising and effective immunotherapies, with significant survival benefits and durable responses in diverse tumor types. However, an increasing number of retrospective studies have found that some patients treated with ICIs experience unusual responses, including accelerated proliferation of tumor cells and rapid progression of the disease, with poor outcomes. Such unexpected adverse events are termed hyperprogressive disease (HPD), and their occurrence suggests that ICIs are detrimental to a subset of cancer patients. HPD is common, with an incidence ranging between 4 and 29% in several cancer types. However, the mechanisms of HPD remain poorly understood, and no clinical predictive factors of HPD have been identified. In this review, we summarize current findings, including retrospective studies and case reports, and focus on several key issues including the defining characteristics, predictive biomarkers, potential mechanisms of HPD, and strategies for avoiding HPD after ICI treatment.


Author(s):  
Allan Relecom ◽  
Maysaloun Merhi ◽  
Varghese Inchakalody ◽  
Shahab Uddin ◽  
Darawan Rinchai ◽  
...  

AbstractImmune checkpoint inhibitors provide considerable therapeutic benefit in a range of solid cancers as well as in a subgroup of hematological malignancies. Response rates are however suboptimal, and despite considerable efforts, predicting response to immune checkpoint inhibitors ahead of their administration in a given patient remains elusive. The study of the dynamics of the immune system and of the tumor under immune checkpoint blockade brought insight into the mechanisms of action of these therapeutic agents. Equally relevant are the mechanisms of adaptive resistance to immune checkpoint inhibitors that have been uncovered through this approach. In this review, we discuss the dynamics of the immune system and of the tumor under immune checkpoint blockade emanating from recent studies on animal models and humans. We will focus on mechanisms of action and of resistance conveying information predictive of therapeutic response.


Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4573
Author(s):  
Céline Pisibon ◽  
Amira Ouertani ◽  
Corine Bertolotto ◽  
Robert Ballotti ◽  
Yann Cheli

The immune system is known to help fight cancers. Ten years ago, the first immune checkpoint inhibitor targeting CTLA4 was approved by the FDA to treat patients with metastatic melanoma. Since then, immune checkpoint therapies have revolutionized the field of oncology and the treatment of cancer patients. Numerous immune checkpoint inhibitors have been developed and tested, alone or in combination with other treatments, in melanoma and other cancers, with overall clear benefits to patient outcomes. However, many patients fail to respond or develop resistance to these treatments. It is therefore essential to decipher the mechanisms of action of immune checkpoints and to understand how immune cells are affected by signaling to be able to understand and overcome resistance. In this review, we discuss the signaling and effects of each immune checkpoint on different immune cells and their biological and clinical relevance. Restoring the functionality of T cells and their coordination with other immune cells is necessary to overcome resistance and help design new clinical immunotherapy strategies. In this respect, NK cells have recently been implicated in the resistance to anti-PD1 evoked by a protein secreted by melanoma, ITGBL1. The complexity of this network will have to be considered to improve the efficiency of future immunotherapies and may lead to the discovery of new immune checkpoints.


2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.


Author(s):  
Mingming Tian ◽  
Si Zhang ◽  
Yujen Tseng ◽  
Xizhong Shen ◽  
Ling Dong ◽  
...  

: Application of immune checkpoint inhibitors (ICIs) is a major breakthrough in the field of cancer therapy, which has displayed tremendous potential in various types of malignancies. However, their response rates range widely in different cancer types and a significant number of patients experience immune-related adverse effects (irAEs) induced by these drugs, limiting the proportion of patients who can truly benefit from ICIs. Gut microbiota has gained increasing attention due to its emerging role in regulating the immune system. In recent years, numerous studies have shown that gut microbiota can modulate antitumor response, as well as decrease the risk of colitis due to ICIs in patients receiving immunotherapy. The present review analyzed recent progress of relevant basic and clinical studies in this area and explored new perspectives to enhance the efficacy of ICIs and alleviate associated irAEs via manipulation of the gut microbiota.


Immunotherapy ◽  
2021 ◽  
Author(s):  
Fausto Petrelli ◽  
Roberto Ferrara ◽  
Diego Signorelli ◽  
Antonio Ghidini ◽  
Claudia Proto ◽  
...  

This study is a meta-analysis of randomized controlled trials involving first-line studies in which immune checkpoint inhibitors were added to chemotherapy and were compared with chemotherapy alone. The primary end point was overall survival (OS). The analyses used random-effects models and the Grading of Recommendations Assessment, Development, and Evaluation system to rate the quality of the evidence. Nine articles were included for qualitative and quantitative synthesis. A meta-analysis of the nine randomized trials showed a significant benefit in terms of OS (hazard ratio: 0.75 [95% CI: 0.66–0.85]; p < 0.01). Only programmed death ligand-1 positive-high cancers derive a significant OS benefit. In this meta-analysis, there is moderate evidence that the addition of immune checkpoint inhibitors to chemotherapy may improve both OS compared with chemotherapy alone.


2019 ◽  
Vol 26 (4) ◽  
pp. 995-999 ◽  
Author(s):  
Steffi Thomas ◽  
Chay Bae ◽  
Tabanor Joy-Ann ◽  
William Traverse

Introduction The landscape for the treatment of metastatic melanoma has been revolutionized with the introduction immune checkpoint inhibitors. Immune checkpoint inhibitors have now become the standard of care for the treatment of cancers. These immune agents including programmed death receptor-1 inhibitors, programmed death-ligand 1 inhibitors and cytotoxic T-lymphocyte antigen-4 inhibitors have shown promising results but have been associated with numerous immune-related complications. Pembrolizumab, a programmed death receptor-1 inhibitor, has been associated with a number of immune-related adverse events affecting multiple organ systems including integument, ocular, endocrine, cardiovascular, pulmonary, renal, gastrointestinal, and musculoskeletal system. Case report We present a case of an 88-year-old Caucasian male with metastatic melanoma of the face with metastasis to the right fifth cranial nerve and into the right cavernous sinus. He underwent resection of the melanoma and was placed on pembrolizumab at 2 mg/kg every three weeks. Interestingly, 24 months on pembrolizumab therapy, he developed corneal erosions, oral and genital ulcerations. Management and outcome Patient completed his 24 months of pembrolizumab and was started on prednisone and colchicine with improvement in his symptoms. At his follow-up eight months, he had recurrence of an oral ulcer. Discussion Here we present a rare case of an elderly male on pembrolizumab who suffered from corneal erosions, oral and genital ulcers, a syndrome similar to Behcet’s disease. Given that pembrolizumab and other immune checkpoint inhibitors are being utilized in the treatment of cancers, physicians should be aware of the wide range immune-related adverse events including the possible Behcet’s-like syndrome presentation.


2019 ◽  
Vol 36 (6) ◽  
pp. 369-377 ◽  
Author(s):  
Gregory A Daniels ◽  
Angela D Guerrera ◽  
Donna Katz ◽  
Jayne Viets-Upchurch

Multiple drugs of a new class of cancer treatments called immune checkpoint inhibitors, which work by enabling the immune system to attack tumour cells, have been approved for a variety of indications in recent years. Immune checkpoints, such as cytotoxic T-lymphocyte antigen-4 and programmed death-1, are part of the normal immune system and regulate immune activation. Treatment with inhibitors of these checkpoints can significantly improve response rates, progression-free survival and overall survival of patients with cancer; it can also result in adverse reactions that present similarly to other conditions. These immune-mediated adverse reactions (IMARs) are most commonly gastrointestinal, respiratory, endocrine or dermatologic. Although patients’ presentations may appear similar to other types of cancer therapy, the underlying causes, and consequently their management, may differ. Prompt recognition is critical because, with appropriate management, most IMARs resolve and patients can continue receiving immune checkpoint inhibitor treatment. Rarely, these IMARs may be life-threatening and escape detection from the usual evaluations in the emergency environment. Given the unusual spectrum and mechanism of IMARs arising from immune checkpoint inhibitors, emergency departmentED staff require a clear understanding of the evaluation of IMARs to enable them to appropriately assess and treat these patients. Treatment of IMARs, most often with high-dose steroids, differs from chemotherapy-related adverse events and when possible should be coordinated with the treating oncologist. This review summarises the ED presentation and management of IMARs arising from immune checkpoint inhibitors and includes recommendations for tools and resources for ED healthcare professionals.


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