Anti-programmed cell death protein 1 (anti-PD1) immunotherapy induced autoimmune polyendocrine syndrome type II (APS-2): a case report and review of the literature

Challenges in autoimmune polyendocrine syndrome type 2 with the full triad induced by anti-programmed cell death 1: a case report and review of the literature

Background

Immune checkpoint inhibitors (ICPis) induce autoimmune diseases, including autoimmune polyendocrine syndrome type 2 (APS-2), which is defined as a combination of at least two of the following endocrinopathies: autoimmune thyroid disease, type 1 diabetes, and Addison's disease. Cases with the full triad are rare. We present a case of an elderly woman who developed APS-2 with the complete triad shortly after starting anti-programmed cell death 1 (anti-PD1) treatment and review the related literature.

Case

A 60-year-old woman, without any personal or family history of autoimmune and endocrine diseases, started the immunotherapy of anti-PD1 (camrelizumab) for squamous cell carcinoma of the urethral meatus. She developed primary hypothyroidism with elevated antibodies to thyroid peroxidase and thyroglobulin after 25 weeks of treatment, and developed primary adrenal insufficiency with adrenal crisis and fulminant type 1 diabetes with ketoacidosis after 45 weeks. Therefore, this patient met the diagnosis of APS-2 and was given multiple hormone replacement including glucocorticoid, levothyroxine and insulin therapy. Continuous improvement was achieved through regular monitoring and titration of the dosage.

Conclusions

Different components of APS-2 may appear at different time points after anti-PD1 administration, and can be acute and life-threatening. A good prognosis can be obtained by appropriate replacement with multiple hormones.

Insights

With the clinical application of ICPis to APS-2, the complexity of its treatment should be paid enough attention.

A Case in Which HLA-DR4 is Involved in the Development of Complex Immune-Related Endocrinological Adverse Events following Combination Therapy with Nivolumab and Ipilimumab

Immune checkpoint inhibitors (ICIs) have become a focal point in cancer immunotherapy, though their utilization is also linked to the occurrence of diverse immune-related adverse events (irAEs). Herein, we present details of a 42-year-old woman diagnosed with a malignant vaginal melanoma who underwent ICI therapy with the combination of nivolumab and ipilimumab. Approximately two months after initiating therapy, the patient manifested destructive thyroiditis and fulminant type 1 diabetes mellitus, thus necessitating intensive insulin therapy. Following the onset of adrenocorticotropic hormone deficiency, frequent hypoglycemic episodes prompted the initiation of replacement therapy with hydrocortisone. Human leukocyte antigen (HLA)-DNA typing revealed the presence of HLA-DRB1∗04 : 05 and DQB1∗04 : 01. HLA-DR4 has been suggested to be associated with the development of multiple endocrine irAEs. This is the first reported case of three endocrine irAEs occurring within a short period, in which the presence of HLA-DR4 may have contributed to the pathogenesis.

Clinically Approved Monoclonal Antibodies-based Immunotherapy: Association With Glycemic Control and Impact Role of Clinical Pharmacist for Cancer Patient Care

PURPOSE

Compared with more conventional, nonspecific therapy options, such as radiotherapy and chemotherapy, monoclonal antibodies (mAbs) constitute a crucial approach of cancer treatment. Multiple autoimmune diseases have been observed during treatment with mAb medications, including autoimmune diabetes mellitus (DM). This study provides a narrative review of clinically approved mAbs in cancer treatment and focuses on the development of hyperglycemia and DM arising from using these therapies. Furthermore, it highlights the critical role of oncology clinical pharmacists in the management of autoimmune DM and patient care while using these medications in an oncology setting.

METHODS

An extensive literature search was conducted using various sources of electronic databases, such as Scopus, Embase, Web of Science, and PubMed, and search engines, such as Google Scholar, for studies on mAb classification, types, mechanisms of action, pharmacokinetic properties, current clinical applications, and the associated common adverse effects with significant recommendations for patient care in an oncology setting, along with focusing on the proposed mechanisms and clinical studies that reported the association of DM after the use of these therapies.

FINDINGS

There are 4 types (murine, chimeric, humanized, and human) and 3 classes (unconjugated, conjugated, and bispecific) of mAbs with several mechanisms of action that can destroy cancer cells, including preventing tumor cell survival cascades, inhibiting tumor growth by interfering with tumor angiogenesis, evading programmed cell death, and bypassing immune checkpoints. However, multiple endocrinopathies, autoimmune diseases, and complications were reported from the use of these medications, including the development of autoimmune DM and diabetic ketoacidosis. These autoimmune disorders were reported most with the use of immune checkpoint inhibitors, including inhibitors of the programmed cell death protein 1 (nivolumab and pembrolizumab), its ligand (atezolizumab, avelumab, and durvalumab), and cytotoxic T-lymphocyte-associated protein 4 (ipilimumab).

IMPLICATIONS

mAbs are considered important approaches for the treatment of many cancer types. However, a high incidence of hyperglycemia, type 1 DM, and diabetic ketoacidosis is observed with the use of these medications, particularly immune checkpoint inhibitors. It is important for oncologic clinical pharmacists to be involved in addressing these autoimmune disorders from the use of these immunotherapies via the provision of patient education, medication adherence support, close monitoring, and follow-up, which will lead to better health-related outcomes and improved patient quality of life.

Autoimmune diabetes from pembrolizumab: A case report and review of literature

BACKGROUND

Immunotherapy, specifically the use of checkpoint inhibitors such as pembrolizumab, has become an important tool in personalized cancer therapy. These inhibitors target proteins on T-cells that regulate the immune response against tumor cells. Pembrolizumab, which targets the programmed cell death 1 receptor on T-cells, has been approved for the treatment of metastatic melanoma and non-small cell lung cancer. However, it can also lead to immune-related side effects, including pneumonitis, colitis, thyroid abnormalities, and rare cases of type 1 diabetes.

CASE SUMMARY

The case presented involves an adult patient in 30s with breast cancer who developed hyperglycemia after receiving pembrolizumab treatment. The patient was diagnosed with diabetic ketoacidosis and further investigations were performed to evaluate for new-onset type 1 diabetes. The patient had a history of hypothyroidism and a family history of breast cancer. Treatment for diabetic ketoacidosis was initiated, and the patient was discharged for close follow-up with an endocrinologist.

CONCLUSION

This literature review highlights the occurrence of diabetic ketoacidosis and new-onset type 1 diabetes in patients receiving pembrolizumab treatment for different types of cancer. Overall, the article emphasizes the therapeutic benefits of immunotherapy in cancer treatment, particularly pembrolizumab, while also highlighting the potential side effect of immune-related diabetes that can occur in a small percentage of patients. Here we present a case where pembrolizumab lead to development of diabetes after a few cycles highlighting one of the rare yet a serious toxicity of the drug.

When Hormones are Being Difficult: A Rare Case and the Literature Review of Pembrolizumab-Induced Polyendocrinopathy

Immune Checkpoint inhibitors (ICIs) such as nivolumab, pembrolizumab, and ipilimumab are monoclonal antibodies against cytotoxic T lymphocyte antigen 4 (CTLA4) or program death (PD)1 and its ligand PDL1. Agents targeting PD1, such as pembrolizumab, have shown widespread efficacy in the past and are also associated with a wide range of immune-related adverse events (irAEs), including endocrine toxicities. A 31-year-old female with a medical history significant for Stage IIb Breast cancer on chemo and immunotherapy (pembrolizumab) presented with nausea, vomiting, and generalized abdominal pain. Laboratory studies showed a blood glucose level of 356 mg/dl, elevated Anion gap 18 meq/L, beta-hydroxybutyrate 46 mg/d, and low C-peptide levels <0.10 ng/ml. The patient was treated for Diabetic Ketoacidosis (DKA). Further testing revealed high Thyroid Stimulating Hormone (TSH) levels along with elevated thyroid peroxidase levels of 38 IU/L. After discharge from the hospital on insulin and levothyroxine therapy, the patient reported increasing fatigue and further testing revealed low cortisol levels <0.5 mcg/dl with elevated ACTH consistent with primary adrenal insufficiency. The patient was started on hydrocortisone therapy with improvement in symptoms. Endocrine toxicities are not uncommon in patients receiving pembrolizumab, but polyendocrinopathy in a relatively rare side effect of pembrolizumab. Only a few cases of pembrolizumab-induced polyendocrinopathy have been reported so far which we have mentioned in this article. While patients are on immunotherapy, close monitoring for clinical signs & symptoms can lead to an early diagnosis, substantially improving morbidity and mortality.

Immune checkpoint inhibitor therapy-induced autoimmune polyendocrine syndrome type II and Crohn’s disease: A case report

BACKGROUND

The development of immune checkpoint inhibitors (ICIs) has heralded a new era in cancer treatment, enabling the possibility of long-term survival in patients with metastatic disease. Unfortunately, ICIs are increasingly implicated in the development of autoimmune diseases.

CASE SUMMARY

We present a man with squamous cell carcinoma of the oropharynx on a combination of teriprizumab, docetaxel, and cisplatin therapy who developed autoimmune polyendocrine syndrome type II (APS-2) including thyroiditis and type 1 diabetes mellitus and Crohn’s disease (CD). He developed thirst, abdominal pain, and fatigue after two-week treatment with the protein 1 ligand inhibitor teriprizumab. Biochemistry confirmed APS-2 and thyrotoxicosis. He was commenced on an insulin infusion. However, his abdominal pain persisted. Follow-up surgery confirmed CD and his abdominal pain was relieved by mesalazine. He was continued on insulin and mesalazine therapy.

CONCLUSION

Immunotherapy can affect all kinds of organs. When clinical symptoms cannot be explained by a single disease, clinicians should consider the possibility of multisystem damage.

A Concerted Vision to Advance the Knowledge of Diabetes Mellitus Related to Immune Checkpoint Inhibitors

The rubric of immune-related (ir) diabetes mellitus (DM) (irDM) encompasses various hyperglycemic disorders related to immune checkpoint inhibitors (ICPis). Beyond sharing similarities with conventional DM, irDM is a distinct, yet important, entity. The present narrative review provides a comprehensive overview of the literature regarding irDM published in major databases from January 2018 until January 2023. Initially considered rare, irDM is increasingly being reported. To advance the knowledge of irDM, the present review suggests a concerted vision comprising two intertwined aspects: a scientific-centered and a patient-centered view. The scientific-centered aspect addresses the pathophysiology of irDM, integrating: (i) ICPi-induced pancreatic islet autoimmunity in genetically predisposed patients; (ii) altered gut microbiome; (iii) involvement of exocrine pancreas; (iv) immune-related acquired generalized lipodystrophy. The patient-centered aspect is both nurtured by and nurturing the four pillars of the scientific-centered aspect: awareness, diagnosis, treatment, and monitoring of irDM. The path forward is a multidisciplinary initiative towards: (i) improved characterization of the epidemiological, clinical, and immunological profile of irDM; (ii) standardization of reporting, management, and surveillance protocols for irDM leveraging global registries; (iii) patient stratification according to personalized risk for irDM; (iv) new treatments for irDM; and (v) uncoupling ICPi efficacy from immunotoxicity.

Endocrine-related adverse conditions in patients receiving immune checkpoint inhibition: an ESE clinical practice guideline

Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment but are associated with significant autoimmune endocrinopathies that pose both diagnostic and treatment challenges. The aim of this guideline is to provide clinicians with the best possible evidence-based recommendations for treatment and follow-up of patients with ICI-induced endocrine side-effects based on the Grading of Recommendations Assessment, Development, and Evaluation system. As these drugs have been used for a relatively short time, large systematic investigations are scarce. A systematic approach to diagnosis, treatment, and follow-up is needed, including baseline tests of endocrine function before each treatment cycle. We conclude that there is no clear evidence for the benefit of high-dose glucocorticoids to treat endocrine toxicities with the possible exceptions of severe thyroid eye disease and hypophysitis affecting the visual apparatus. With the exception of thyroiditis, most endocrine dysfunctions appear to be permanent regardless of ICI discontinuation. Thus, the development of endocrinopathies does not dictate a need to stop ICI treatment.

Unraveling the mechanism of alkaloids from Sophora alopecuroides Linn combined with immune checkpoint blockade in the treatment of non-small cell lung cancer based on systems pharmacology

Quinolizidine alkaloids, as essential active ingredients extracted from Sophora alopecuroides Linn (SAL), have been proven to be pharmacologically active in a variety of cancers including non-small cell lung cancer (NSCLC). However, whether these alkaloids have substantial benefits in combination with immune checkpoint blockade (ICB) for the treatment of NSCLC is unknown. Here, we explore the potential of these alkaloids in combination with ICB therapy based on a systems pharmacology and bioinformatics approach. We found that 37 alkaloids in SAL have highly similar characteristics in the molecular skeleton, pharmacological properties, and targets. The expression of targets of these alkaloids are significantly correlated with the infiltration level of tumor infiltrating lymphocytes and the expression levels of multiple immune checkpoints in NSCLC. They share similar molecular mechanisms in antitumor immunity. Sophocarpine (Sop) is one of the most representative constituents of these alkaloids. We demonstrated that the Sop promotes PD-L1 expression to improve the effects of PD-L1 blockade treatment via the ADORA1-ATF3 axis. In conclusion, our study identified these alkaloids as promising candidates for the treatment of NSCLC, either alone or in combination with ICB, with potential value for drug development and may provide a promising strategy for improving the survival of NSCLC patients.

Sintilimab-induced autoimmune diabetes: A case report and review of the literature

BACKGROUND

With the widespread application of immune checkpoint inhibitor (ICI) therapy, the number of immune-related adverse effects (irAEs) has increased over the years. Autoimmune diabetes mellitus (DM) is a rare irAEs of ICIs and can be troublesome and life threatening.

CASE SUMMARY

We report a 78-year-old woman with no history of diabetes who presented with hyperglycemia up to 23.4 mmol/L (random blood glucose level) after 14 courses of sintilimab. Hemoglobin A1c was 8.2%, fasting insulin was 0.29 mIU/mL, and fasting C-peptide was decreased to a level with negative autoantibodies. Combing her medical history and laboratory examination, she was diagnosed with programmed cell death (PD)-1-inhibitor-induced, new-onset autoimmune DM. After controlling her blood glucose, she was treated with daily insulin by subcutaneous injection. She was allowed to continue anti-PD-1 therapy and she still obtained some therapeutic efficacy. We also reviewed some published cases (n = 36) of PD-1/PD-ligand 1 (PD-L1) inhibitor-induced DM. We also discuss potential pathogenic mechanisms, clinical features, prognostic markers (β cell antibodies, human leukocyte antigen type, PD-L1 Level) of this rare adverse effect.

CONCLUSION

It is important for all clinicians to be aware of DM as an irAEs of ICIs.

[Usefulness of an anti-mouse cerebellar tissue-derived antigen antibody test in predicting immunotherapy efficacy in patients with idiopathic cerebellar ataxia]

BACKGROUND

Autoimmune cerebellar ataxia (AICA) is a general term for diseases in which the cerebellum is damaged by an autoimmune mechanism. For the diagnosis of the AICA, anti-thyroid antibodies (anti-thyroid peroxidase antibody and anti-thyroglobulin antibody), anti-glutamic acid decarboxylase (GAD) antibodies, and anti-gliadin antibodies are measured. Immunotherapy is known to be effective for AICA, but some patients with effective immunotherapy lack autoantibodies associated with cerebellar ataxia. The purpose of this study was to clarify whether the effectiveness of immunotherapy in patients with suspected AICA could be predicted by anti-mouse cerebellar tissue-derived antigen antibody tests.

METHODS

This study was conducted on 25 patients with idiopathic cerebellar ataxia (excluding multiple system atrophy, hereditary spinocerebellar degeneration, cancer-bearing patients, and patients taking phenytoin) who received immunotherapy from 2005 to 2016 at Tokyo Medical University Hachioji Medical Center. The patients were suspected of having AICA because they were positive for cerebellar ataxia-related autoantibodies (anti-thyroid antibody, anti-GAD antibody, anti-gliadin antibody, or anti-transglutaminase 6 antibody) or other autoantibodies. Antibodies that bind to mouse cerebellar tissue-derived antigens were defined as "anti-mouse cerebellar tissue-derived antigen antibodies" in this study, and their IgG-class antibodies were comprehensively measured using a slot blot.

RESULTS

Anti-mouse cerebellar tissue-derived antigen antibody test results were correlated with immunotherapy efficacy. Furthermore, the combination of anti-mouse cerebellar tissue-derived antigen and anti-GAD antibody tests could predict the effectiveness of immunotherapy with 83% sensitivity and 100% specificity, while the combination of the anti-mouse cerebellar tissue-derived antigen, anti-GAD, and anti-gliadin (IgA class) antibody tests could predict the effectiveness of immunotherapy with 94% sensitivity and 86% specificity.

CONCLUSION

Anti-mouse cerebellar tissue-derived antigen antibody tests could help to provide useful information for immunotherapy administration to patients with idiopathic cerebellar ataxia suspected to be AICA.

Mechanisms and therapeutic strategies of immune checkpoint molecules and regulators in type 1 diabetes

BACKGROUND

Considered a significant risk to health and survival, type 1 diabetes (T1D) is a heterogeneous autoimmune disease characterized by hyperglycemia caused by an absolute deficiency of insulin, which is mainly due to the immune-mediated destruction of pancreatic beta cells.

SCOPE OF REVIEW

In recent years, the role of immune checkpoints in the treatment of cancer has been increasingly recognized, but unfortunately, little attention has been paid to the significant role they play both in the development of secondary diabetes with immune checkpoint inhibitors and the treatment of T1D, such as cytotoxic T-lymphocyte antigen 4(CTLA-4), programmed cell death protein-1(PD-1), lymphocyte activation gene-3(LAG-3), programmed death ligand-1(PD-L1), and T-cell immunoglobulin mucin protein-3(TIM-3). Here, this review summarizes recent research on the role and mechanisms of diverse immune checkpoint molecules in mediating the development of T1D and their potential and theoretical basis for the prevention and treatment of diabetes.

MAJOR CONCLUSIONS

Immune checkpoint inhibitors related diabetes, similar to T1D, are severe endocrine toxicity induced with immune checkpoint inhibitors. Interestingly, numerous treatment measures show excellent efficacy for T1D via regulating diverse immune checkpoint molecules, including co-inhibitory and co-stimulatory molecules. Thus, targeting immune checkpoint molecules may exhibit potential for T1D treatment and improve clinical outcomes.

NF-κB: At the Borders of Autoimmunity and Inflammation

The transcription factor NF-κB regulates multiple aspects of innate and adaptive immune functions and serves as a pivotal mediator of inflammatory response. In the first part of this review, we discuss the NF-κB inducers, signaling pathways, and regulators involved in immune homeostasis as well as detail the importance of post-translational regulation by ubiquitination in NF-κB function. We also indicate the stages of central and peripheral tolerance where NF-κB plays a fundamental role. With respect to central tolerance, we detail how NF-κB regulates medullary thymic epithelial cell (mTEC) development, homeostasis, and function. Moreover, we elaborate on its role in the migration of double-positive (DP) thymocytes from the thymic cortex to the medulla. With respect to peripheral tolerance, we outline how NF-κB contributes to the inactivation and destruction of autoreactive T and B lymphocytes as well as the differentiation of CD4⁺-T cell subsets that are implicated in immune tolerance. In the latter half of the review, we describe the contribution of NF-κB to the pathogenesis of autoimmunity and autoinflammation. The recent discovery of mutations involving components of the pathway has both deepened our understanding of autoimmune disease and informed new therapeutic approaches to treat these illnesses.

Autoimmune polyendocrine syndrome induced by immune checkpoint inhibitors: a systematic review

OBJECTIVE

To summarize the clinical characteristics and immunological and genetic features of patients who developed autoimmune polyendocrine syndrome type II (APS-2) after treatment with immune checkpoint inhibitors (ICIs).

DESIGN AND METHODS

Several databases (MEDLINE/EMBASE/Cochrane) were searched for studies published between January 2000 and February 2020 involving patients with two or more endocrine disorders after ICI therapy.

RESULTS

Our final review included 22 articles comprising 23 patients (median age 56 years; 65.2% male patients). Of these patients, 60.9% received anti-programmed cell death 1 (PD-1) therapy, 17.4% received anti-programmed cell death ligand 1 (PD-L1) therapy, and 4.3% received anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) monotherapy. Patients underwent a median of four treatment cycles before the onset of the primary adverse event; the median time of onset was 8.5 weeks. Endocrine organs affected by ICI administration included the thyroid gland (18/23, 78.3%), pancreatic islets (17/23, 73.9%), pituitary gland (11/23, 47.8%), and adrenal gland (2/23, 8.7%). Related autoantibodies were detected in 65.2% of patients. In patients with diabetes, glutamic acid decarboxylase antibody was closely related to the development of diabetes ketoacidosis. The human leukocyte antigen genotype was reported in 34.8% (8/23) of patients, 5 (62.5%) of which had risk genotypes.

CONCLUSIONS

As a serious adverse event of ICI treatment, APS-2 is presented with abrupt initiation time and rapid development. Physicians should be aware of potential endocrine disorders and continue monitoring hormone status when treating cancer patients with ICIs.

Autoimmune polyendocrine syndrome type 3, characterized by autoimmune thyroid disease, type 1 diabetes mellitus, and isolated ACTH deficiency, developed during adjuvant nivolumab treatment

Autoimmune polyendocrine syndrome (APS) is one of the life-threatening immune-related adverse events (irAEs). We firstly report a case of APS induced by adjuvant nivolumab therapy. Clinicians should be aware of the potential risks of developing severe irAEs when applying adjuvant immunotherapy.

Immune Checkpoint Inhibitor-Induced Adrenalitis and Primary Adrenal Insufficiency: Systematic Review and Optimal Management

OBJECTIVE

Immune checkpoint inhibitors (ICIs) targeting cytotoxic T-lymphocyte antigen 4 or programmed death 1 and its ligand (programmed death ligand 1) have been approved for the treatment of a variety of cancers. However, ICI therapy is associated with a risk of immune-related adverse events. In this study, we reviewed reported cases of adrenalitis and primary adrenal insufficiency (PAI)-rare but lethal endocrine immune-related adverse events-in patients who underwent ICI therapy.

METHODS

We searched multiple databases (PubMed, Web of Science, Cochrane, and Scopus) up to February 2020 for case reports on adrenalitis and PAI caused by ICIs.

RESULTS

We identified 15 case reports on ICI-induced adrenalitis and PAI and reviewed their clinical presentation, characteristics, immunologic and imaging features, and treatment. We also developed a screening strategy for PAI in patients treated with ICIs.

CONCLUSION

Given the morbidity and mortality associated with acute adrenal crisis, physicians-especially endocrinologists and oncologists-should be aware of this particular risk. PAI caused by autoimmune adrenalitis predominantly occurs in patients treated with programmed death 1 inhibitor monotherapy. PAI often coexists with other endocrinopathies and requires mineralocorticoid as well as glucocorticoid replacement. Even after withdrawal of ICIs, PAI can persist and requires lifelong replacement therapy.

ICPis-Induced Autoimmune Polyendocrine Syndrome Type 2: A Review of the Literature and a Protocol for Optimal Management

CONTEXT

Immune checkpoint inhibitors (ICPis) targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), and its ligand (PD-L1) are now approved to treat a variety of cancers. However, ICPis therapy is associated with a risk of immune-related adverse events (irAEs). Autoimmune polyendocrine syndrome type 2 (APS-2) is a rare endocrine irAE.

EVIDENCE ACQUISITION

Several databases (PubMed, Web of Science, Cochrane Central Registry of Controlled Trials, ClinicalTrials.gov, and Scopus) were searched up to February 18, 2020, for case reports on endocrine irAEs and ICPis. The reported side effects and adverse events of the ICPis therapy in the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) adverse events pharmacovigilance registries are also included.

EVIDENCE SYNTHESIS

Here, we provide an overview of all published and reported cases (n = 30) of ICPis-induced APS-2. We summarize the clinical characteristics, autoantibodies, human leukocyte antigen (HLA) genotypes, and therapies and propose an APS-2 screening strategy.

CONCLUSIONS

Given the life-threatening risks of endocrine dysfunction if it is not promptly recognized (such as diabetic ketoacidosis and acute adrenal crisis), physicians (especially endocrinologists and oncologists) should be familiar with APS-2. After diagnosis of an autoimmune disease induced by ICPis (especially PD-1 inhibitors), patients with a high-risk HLA allele (HLA-DR4) require close monitoring for the development of APS-2.

Management of endocrine immune-related adverse events of immune checkpoint inhibitors: an updated review

Immune checkpoint inhibitors (ICIs) belong to a new group of anticancer drugs targeting T-cell proteins involved in the activation of immune response toward malignancies. Their introduction into clinical practice was a milestone in modern cancer treatment. However, the significant advantage of ICIs over conventional chemotherapy in terms of therapeutic efficacy is accompanied by new challenges related to specific side effects. ICI-induced immune system activation could lead to the loss of self-tolerance, presenting as autoimmune inflammation and dysfunction of various tissues and organs. Thus, the typical side effects of ICIs include immune-related adverse events (irAEs), among which endocrine irAEs, affecting numerous endocrine glands, have been commonly recognized. This review aimed to outline the current knowledge regarding ICI-induced endocrine disorders from a clinical perspective. We present updated information on the incidence and clinical development of ICI-induced endocrinopathies, including the most frequent thyroiditis and hypophysitis, the rarely observed insulin-dependent diabetes mellitus and primary adrenal insufficiency, and the recently described cases of hypoparathyroidism and lipodystrophy. Practical guidelines for monitoring, diagnosis, and treatment of ICI-related endocrine toxicities are also offered. Rising awareness of endocrine irAEs among oncologists, endocrinologists, and other health professionals caring for patients receiving ICIs could contribute to better safety and efficacy. As immunotherapy becomes widespread and approved for new types of malignancies, increased incidences of endocrine irAEs are expected in the future.