The side effects of immune checkpoint inhibitor therapy on the endocrine system

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

Reversible elevation of creatine kinase and creatinine caused by sintilimab-induced hypothyroidism: A case report

RATIONALE

Programmed cell death (PD) -1 inhibitors has significantly improved the prognosis of cancer patients by enhancing antitumor immune responses. However, PD-1 inhibitors are associated with immune-related adverse events, some of which are rare and potentially life-threatening. Thus far, elevated creatine kinase (CK) and creatinine caused by a novel PD-1 inhibitor (sintilimab)-induced hypothyroidism has not yet been reported.

PATIENT CONCERNS

A 63-year-old male patient with esophageal cancer who developed hypothyroidism accompanied by unexplained increases in CK and creatinine after sintilimab treatment.

DIAGNOSIS

Since the increases in CK and creatinine paralleled the decrease in thyroxine, after excluding other potential conditions, we speculated that the muscular and renal dysfunction might be caused by sintilimab-induced hypothyroidism.

INTERVENTIONS AND OUTCOMES

As the patient's thyroid function improved with levothyroxine replacement therapy, the levels of CK and creatinine concomitantly returned to normal.

CONCLUSION AND LESSONS

The elevated CK and creatinine levels in this patient were caused by sintilimab-induced hypothyroidism. Our case highlights the importance of keeping PD-1 induced hypothyroidism in mind when patients present with unexplained increased levels of CK and creatinine. Hypothyroidism-related muscular and renal dysfunctions, which can be restored with thyroid hormone replacement, need to be identified early and treated promptly so that unnecessary examinations and treatments can be avoided in these patients.

Immune Checkpoints and Graves' Disease, Thyroid Eye Disease, and Orbital Myopathy: A Comprehensive Review

Immune checkpoints (ICPs) are essential regulators of the immune system, ensuring a delicate balance between self-tolerance and autoimmune responses. ICP therapy is a rapidly growing cancer treatment strategy that inhibits the interaction between ICPs and their ligands. This biological interaction increases the ability of the immune system in combating cancer. However, in some cases, the use of these agents may lead to immune hyperactivity and, subsequently, autoimmune diseases. Graves' disease (GD), thyroid eye disease (TED), and orbital myopathy are complex autoimmune disorders characterized by the production of autoantibodies. The emergence of these treatment-related adverse events underscore the critical need for a deeper understanding of the immune-checkpoint axis in autoimmune diseases. In this review article, we provide a comprehensive survey of the biological mechanisms of ICPs that are most frequently targeted in cancer therapy, including CTLA-4, PD-1, PDL-1, and LAG3. Furthermore, we investigate the latest scientific findings on the adverse events associated with the inhibition of these ICPs. This paper will particularly focus on the potential risks these complications pose to ocular and orbital tissues, which are a concern in the context of cancer treatment.

Thyroid disorders induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are a revolutionary class of drugs that powerfully contribute to cancer therapy by harnessing the immune system to fight malignancies. However, their successful use as anti-cancer drugs is accompanied by a wide spectrum of immune-related adverse effects (irAEs), including endocrinopathies. Among them, thyroid dysfunction stands out as one of the most common endocrinopathies induced by ICI therapy and surfaces as a prominent concern. Destructive thyroiditis is the pathophysiological basis shared by the most common patterns of thyrotoxicosis followed by hypothyroidism and isolated hypothyroidism. Diagnostic approach is guided by clinical manifestation, laboratory evaluation and imaging modalities. Treatment approaches range from the substitution of levothyroxine to the utilization of beta blockers, depending on the extent of thyroid dysfunction's severity. While the medical community is dealing with the evolution and complexities of immunotherapy, recognizing and effectively managing ICI-induced thyroid dysfunction emerged as crucial for enhancing patient safety and achieving improved outcomes. The aim of this review is to navigate the significance of ICI-induced thyroid dysfunction unraveling the various patterns, underlying mechanisms, diagnostic approaches, and treatment strategies. It, also, highlights the impact of various factors such as cancer subtype, ICI dosage, age, and genetic susceptibility on the risk of experiencing dysfunction.

Selective activation of IFNγ-ipilimumab enhances the therapeutic effect and safety of ipilimumab

INTRODUCTION

Immune checkpoint inhibitor therapy is a highly promising strategy for clinical treatment of cancer. Among these inhibitors, ipilimumab stands out for its ability to induce cytotoxic T cell proliferation and activation by binding to CTLA-4. However, ipilimumab also gives rise to systemic immune-related adverse effects and tumor immune evasion, limiting its effectiveness.

OBJECTIVES

We developed IFNγ-ipilimumab and confirmed that the addition of INF-γ does not alter the fundamental properties of ipilimumab.

RESULTS

IFNγ-ipilimumab can be activated by matrix metalloproteinases, thereby promoting the IFNγ signaling pathway and enhancing the cytotoxicity of T cells. In vivo studies demonstrated that IFNγ-ipilimumab enhances the therapeutic effect of ipilimumab against colorectal cancer by increasing CD8+ and CD4+ lymphocyte infiltration into the tumor area and inducing MHC-I expression in tumor cells. Mice treated with IFNγ-ipilimumab showed higher survival rates and body weight, as well as lower CD4+ and CD8+ lymphocyte activation rates in the blood and reduced organ damage.

CONCLUSION

IFNγ-ipilimumab improved the effectiveness of ipilimumab while reducing its side effects. It is likely that future immunotherapies would rely on such antibodies to activate local cancer cells or immune cells, thereby increasing the therapeutic effectiveness of cancer treatments and ensuring their safety.

Incidence of Diabetes Mellitus in patients treated with immune checkpoint inhibitors (ICI) therapy - A Comprehensive Cancer Center experience

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment and more patients are receiving ICIs than before. Although this has improved cancer care but so has the increase in the incidence of immune-related adverse events (irAEs) including endocrinopathies. ICI-induced diabetes mellitus (DM) is a rare irAE with an approximate incidence of 1%. Due to paucity of data in literature about ICI-induced DM, we conducted a study to report the incidence and characteristics of new onset and worsening of DM in patients treated with ICIs.

METHODS

We conducted a retrospective review of patients who received ICIs during 10-year period. We identified patients with newly diagnosed DM and worsening of preexisting DM.

FINDINGS

Among 2,477 patients who received one or multiple ICIs, 14 patients developed new onset DM and 11 patients experienced worsening of pre-existing DM. Median time to new onset or worsening DM from ICI treatment initiation was ∼12 weeks. Median hemoglobin A1c was 6·2% at baseline and 8·5% at the onset of ICI-induced DM. Seven patients presented with diabetes ketoacidosis (DKA), all in the new onset group. (p= 0·02) No significant difference was observed between two groups regarding personal history of autoimmune disorder or family history of DM. (p>0·05) Positive autoantibodies were found in three patients [two with Glutamic Acid Decarboxylase (GAD65) antibodies and one with insulin autoantibodies (IAA)].

INTERPRETATION

The incidence of new onset and worsening DM in patients treated with ICIs was 1·01%.

Hypothyroidism After Use of Immune Checkpoint Inhibitor Therapy in Patient With Graves' Disease: Cure?

Immune checkpoint inhibitors (ICIs) are frequently used as treatment for many malignancies. Immune-related adverse events (irAEs) due to use of ICIs are common. Thyroid involvement is the most common endocrine irAE. Here, we present an unusual case of Graves' disease potentially cured due to destructive thyroiditis caused by inflammation due to ICIs. Thyroid irAEs are more common with programmed cell death protein-1 (PD-1) inhibitor or programmed cell death-ligand 1 (PD-L1) inhibitors than cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors. Baseline and serial monitoring of thyroid function tests is recommended.

APPROACH TO THE PATIENT WITH IMMUNE CHECKPOINT INHIBITOR-ASSOCIATED ENDOCRINE DYSFUNCTION

Immune checkpoint inhibitors (ICI) are cancer therapies that are approved in at least 19 different cancers. They function by stimulating immune cell responses against cancer, and their toxicities comprise a host of autoinflammatory syndromes that may impact any organ system. Endocrine toxicities occur in as high as 25-50% of ICI recipients, depending on the treatment regimen used. These toxicities vary in severity from mild, asymptomatic cases of subclinical hypothyroidism to severe, fatal cases of adrenal crisis, thyroid dysfunction, or diabetic ketoacidosis. Thus, timely recognition and treatment is critical. Herein, we present clinical cases of ICI-induced thyroid dysfunction, hypophysitis, and insulin-dependent diabetes mellitus. We use these cases to discuss the screening, diagnosis, and management of ICI-associated endocrine dysfunction.

Drug Repurposing to Enhance Antitumor Response to PD-1/PD-L1 Immune Checkpoint Inhibitors

Monoclonal antibodies targeting the PD-1/PD-L1 immune checkpoint have considerably improved the treatment of some cancers, but novel drugs, new combinations, and treatment modalities are needed to reinvigorate immunosurveillance in immune-refractory tumors. An option to elicit antitumor immunity against cancer consists of using approved and marketed drugs known for their capacity to modulate the expression and functioning of the PD-1/PD-L1 checkpoint. Here, we have reviewed several types of drugs known to alter the checkpoint, either directly via the blockade of PD-L1 or indirectly via an action on upstream effectors (such as STAT3) to suppress PD-L1 transcription or to induce its proteasomal degradation. Specifically, the repositioning of the approved drugs liothyronine, azelnidipine (and related dihydropyridine calcium channel blockers), niclosamide, albendazole/flubendazole, and a few other modulators of the PD-1/PD-L1 checkpoint (repaglinide, pimozide, fenofibrate, lonazolac, propranolol) is presented. Their capacity to bind to PD-L1 or to repress its expression and function offer novel perspectives for combination with PD-1 targeted biotherapeutics. These known and affordable drugs could be useful to improve the therapy of cancer.

Thyroid-related adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors, namely anti-CTLA-4, anti-PD-1 and anti-PD-L1 monoclonal antibodies, have emerged in the last decade as a novel form of cancer treatment, promoting increased survival in patients. As they tamper with the immune response in order to destroy malignant cells, a new type of adverse reactions has emerged, known as immune-related adverse events (irAEs), which frequently target the endocrine system, especially the thyroid and hypophysis. Thyroid irAEs include hyperthyroidism, thyrotoxicosis, hypothyroidism and a possibly life-threatening condition known as the "thyroid storm". Early prediction of occurrence and detection of the thyroid irAEs should be a priority for the clinician, in order to avoid critical situations. Moreover, they are recently considered both a prognostic marker and a means of overseeing treatment response, since they indicate an efficient activation of the immune system. Therefore, a multidisciplinary approach including both oncologists and endocrinologists is recommended when immune checkpoint inhibitors are used in the clinic.