Diabetes associated with immune checkpoint inhibition: presentation and management challenges

Sintilimab-induced diabetes mellitus and thyroid dysfunction in patient with gastric adenocarcinoma: A case report and literature review

RATIONALE

Immune checkpoint inhibitors bring hope to cancer patients but may also lead to severe immune-related adverse events (irAEs). Although irAEs during treatment are well-characterized, delayed immune-related events (DIRE) remain underreported. Here, we report a case of sintilimab-induced delayed immune-related diabetes mellitus, accompanied by ICI-related thyroid disease (ICI-TD). Cases involving both ICI-TD and ICI-related diabetes mellitus (ICI-DM) are also relatively rare. This study systematically aggregates dual endocrine irAEs to provide valuable insights for clinical practice.

PATIENT CONCERNS

A 60-year-old Chinese male diagnosed with gastric adenocarcinoma received a multimodal treatment regimen consisting of sintilimab, chemotherapy, and apatinib. He completed 3 cycles of chemotherapy and 4 cycles of sintilimab. Due to disease progression, sintilimab was discontinued, but apatinib was continued for an additional 1 month. No further antitumor therapy was administered afterward. Four months later, he was admitted to the emergency department due to persistent nausea, vomiting, and abdominal pain.

DIAGNOSES

Thyroid dysfunction induced by sintilimab was identified during treatment. His laboratory tests contributed to the diagnosis of diabetes ketoacidosis. Fulminant type 1 diabetes mellitus attributed to sintilimab met diagnostic criteria: plasma glucose 42.01 mmol/L, glycated hemoglobin 7.5%, C-peptide <0.02 µg/L, and negative islet autoantibodies.

INTERVENTIONS

Levothyroxine replacement therapy was initiated for hypothyroidism, whereas diabetes ketoacidosis during hospitalization required intensive insulin therapy combined with fluid resuscitation.

OUTCOMES

The patient exhibited persistent blood glucose fluctuations during hospitalization, including 2 hypoglycemic episodes. Post-treatment stabilization required basal-bolus insulin at discharge, with continued levothyroxine for hypothyroidism.

LESSONS

We report a rare case of concurrent ICI-TD and ICI-DM following sintilimab therapy. This case underscores the potential for DIRE, with onset occurring months posttreatment. Combined with a systematic review of existing cases, this study provides critical insights into surveillance strategies and pathogenesis of irAEs.

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.

Extraislet expression of islet antigen boosts T cell exhaustion to partially prevent autoimmune diabetes

Persistent antigen exposure results in the differentiation of functionally impaired, also termed exhausted, T cells which are maintained by a distinct population of precursors of exhausted T (TPEX) cells. T cell exhaustion is well studied in the context of chronic viral infections and cancer, but it is unclear whether and how antigen-driven T cell exhaustion controls progression of autoimmune diabetes and whether this process can be harnessed to prevent diabetes. Using nonobese diabetic (NOD) mice, we show that some CD8+ T cells specific for the islet antigen, islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) displayed terminal exhaustion characteristics within pancreatic islets but were maintained in the TPEX cell state in peripheral lymphoid organs (PLO). More IGRP-specific T cells resided in the PLO than in islets. To examine the impact of extraislet antigen exposure on T cell exhaustion in diabetes, we generated transgenic NOD mice with inducible IGRP expression in peripheral antigen-presenting cells. Antigen exposure in the extraislet environment induced severely exhausted IGRP-specific T cells with reduced ability to produce interferon (IFN)γ, which protected these mice from diabetes. Our data demonstrate that T cell exhaustion induced by delivery of antigen can be harnessed to prevent autoimmune diabetes.

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.

Recent advances in immune checkpoint inhibitor-induced type 1 diabetes mellitus

As a new group of anticancer drugs, immune checkpoint inhibitors (ICIs) have exhibited favorable antitumor efficacy in numerous malignant tumors. Anti-cytotoxic T lymphocyte associated antigen-4 (CTLA-4), anti-programmed cell death-1 (PD-1) and anti-programmed cell death ligand-1 (PD-L1) are three kinds of ICIs widely used in clinical practice. However, ICI therapy (monotherapy or combination therapy) is always accompanied by a unique toxicity profile known as immune-related adverse events (irAEs) affecting multiple organs. The endocrine glands are common targets of irAEs induced by ICIs, which cause type 1 diabetes mellitus (T1DM) when the pancreas is affected. Although the incidence rate of ICI-induced T1DM is rare, it will always lead to an irreversible impairment of β-cells and be potentially life-threatening. Hence, it is vital for endocrinologists and oncologists to obtain a comprehensive understanding of ICI-induced T1DM and its management. In our present manuscript, we have reviewed the epidemiology, pathology and mechanism, diagnosis, management, and treatments of ICI-induced T1DM.

Monitoring immunomodulation strategies in type 1 diabetes

Type 1 diabetes (T1D) is a T-cell mediated autoimmune disease. Short-term treatment with agents targeting T cells, B cells and inflammatory cytokines to modify the disease course resulted in a short-term pause in disease activity. Lessons learnt from these trials will be discussed in this review. It is expected that effective disease-modifying agents will become available for use in earlier stages of T1D. Progress has been made to analyze antigen-specific T cells with standardization of T cell assay and discovery of antigen epitopes but there are many challenges. High-dimensional profiling of gene, protein and TCR expression at single cell level with innovative computational tools should lead to novel biomarker discovery. With this, assays to detect, quantify and characterize the phenotype and function of antigen-specific T cells will continuously evolve. An improved understanding of T cell responses will help researchers and clinicians to better predict disease onset, and progression, and the therapeutic efficacy of interventions to prevent or arrest T1D.

Hyperglycaemia following immune checkpoint inhibitor therapy-Incidence, aetiology and assessment

AIMS

We systematically studied the presence of hyperglycaemia during treatment with Immune Checkpoint Inhibitors (ICPI) for cancer, in those with and without diabetes at baseline, and determined the cause of new-onset hyperglycaemia, METHODS: Retrospective review of electronic records of those receiving an ICPI for melanoma, lung or renal cancer.

RESULTS

Overall, 959 participants were included. In this study, 103 had diabetes at baseline (10.7%). Those with lung cancer had the highest frequency of diabetes; 131 people had hyperglycaemia (defined as at least one glucose ≥11.1 mmol/L) in the year after starting an ICPI. The incidence was 55% in those with diabetes at baseline, and 8.6% in those without baseline diabetes. Among 74 with new-onset hyperglycaemia (without pre-existing diabetes) 76% was attributable to steroid induced diabetes, with 9.5% due to ICPI Induced diabetes resembling type 1 diabetes.

CONCLUSIONS

Hyperglycaemia is common in persons receiving an ICPI for cancer, including 8.6% of those without known diabetes. While much of this is due to glucocorticoid use, care is needed to avoid missing those with ICPI-induced diabetes who are at risk of diabetic ketoacidosis, which is a medical emergency.

Clinical characteristics and outcomes of immune checkpoint inhibitor-induced diabetes mellitus

•

This article summarized a total of 172 published cases of immune checkpoint inhibitor (ICI)-induced diabetes mellitus (DM).

•

Found that glutamic acid decarboxylase antibodies positivity is related to an earlier onset of ICI-induced diabetes and a higher frequency of diabetic ketoacidosis development.

•

Presented a case of ICI-induced DM following obvious lipase and amylase elevation and discussed possible relationship between ICI-associated injuries to pancreatic exocrine function and endocrine function.

Objective

To better understand immune checkpoint inhibitor (ICI)-induced diabetes mellitus (DM) in cancer patients.

Design and method

We present a case of ICI-induced diabetic ketoacidosis (DKA) and conduct a systematic review of the PubMed and Web of Science databases up to September 2021 to identify all published cases of ICI-induced diabetes.

Results

In addition to our case, a total of 171 published cases were identified during the literature search. Summary and statistical analyzes were conducted for all 172 cases. The median onset time from ICI initiation to DM diagnosis was 12 weeks (range: 0–122). DKA was present in 67.4% (116/172) of the cases, and low C-peptide levels were detected in 91.8% (123/134), indicating an acute onset of diabetes. Patients with positive glutamic acid decarboxylase antibodies (GADA) had an earlier onset of ICI-induced diabetes (median time 7 weeks vs. 16 weeks for GADA-negative patients, p < 0.001) and a higher frequency of DKA development (82.8 vs. 62.1%, p = 0.006). All but two patients developed insulin-dependent diabetes permanently. Immunotherapy rechallenge was reported in 53 cases after glycemia was well controlled.

Conclusion

ICI-induced DM is a serious adverse event that often presents with life-threatening ketoacidosis. GADA positivity is related to an earlier onset of ICI-induced diabetes and a higher frequency of DKA development. Close monitoring of glucose levels is needed in patients receiving ICI treatment. ICI-induced DM is usually insulin-dependent since damage to β cells is irreversible. On the premise of well-controlled glycemia, immunotherapy rechallenge is feasible.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGY (AACE) DISEASE STATE CLINICAL REVIEW EVALUATION AND MANAGEMENT OF IMMUNE CHECKPOINT INHIBITOR-MEDIATED ENDOCRINOPATHIES: A PRACTICAL CASE-BASED CLINICAL APPROACH

OBJECTIVE

The aim of this case-based clinical review is to provide a practical approach for clinicians regarding the management of patients with immune checkpoint inhibitor (ICI)-mediated endocrinopathies.

METHODS

A literature search was conducted using PubMed, Embase and Scopus, and appropriate keywords. The discussions and strategies for diagnosis and management of ICI-mediated endocrinopathies are based on evidence available from prospective randomized clinical studies, cohort studies, cross-sectional studies, case-based studies, and expert consensus.

RESULTS

Immunotherapy with ICIs has transformed the treatment landscape of diverse cancer types, but frequently results in immune-mediated endocrinopathies that can cause acute and persistent morbidity, and rarely, death. The patterns of endocrinopathies differ between inhibitors of the CTLA-4 and PD-1/PD-L1 pathways, but most often involve the thyroid and pituitary glands. Less common but important presentations include insulin-deficient diabetes mellitus, primary adrenal insufficiency, primary hypoparathyroidism, central diabetes insipidus, primary hypogonadism, and pancreatitis with or without subsequent progression to diabetes or exocrine insufficiency.

CONCLUSION

In recent years, with increasing numbers of cancer patients being treated with ICIs, more clinicians in a variety of specialties are called upon to diagnose and treat ICI-mediated endocrinopathies. Herein, we review case scenarios of various clinical manifestations, and emphasize the need for a high index of clinical suspicion by all clinicians caring for these patients including endocrinologists, oncologists, primary care providers, and emergency department physicians. We also provide diagnostic and therapeutic approaches for ICI-induced endocrinopathies, and we propose that patients on ICI-therapy be evaluated and treated in a multidisciplinary team in collaboration with endocrinologists.

The changing clinical spectrum of endocrine adverse events in cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several malignancies, improving patient survival and quality of life. Endocrinopathies have emerged as a clinically significant group of immune-related adverse events (IRAEs). Although the mechanism of ICI toxicities has not been clarified, inhibition of immune checkpoints reduces immune tolerance to autoantigens, resulting in the development of autoimmunity disorders. We report current evidence regarding endocrine IRAEs that may have diagnostic and therapeutic implications. Management should be focused on a multidisciplinary approach to reach a prompt diagnosis and an appropriate and safe treatment.

Immune checkpoint inhibitor-induced diabetes mellitus with pembrolizumab

An 81-year-old woman with a background of metastatic melanoma on pembrolizumab with no history of diabetes was brought into the emergency department with polyuria, polydipsia and weight loss. The initial assessment was consistent with severe diabetic ketoacidosis (DKA) and prerenal acute kidney injury with no clinical evidence of infection. The patient was treated with fluid resuscitation and an insulin infusion and eventually transitioned to a basal-bolus insulin regime, which was continued after discharge. Diabetes autoantibody screen returned negative, and she was diagnosed with immune checkpoint inhibitor–induced diabetes mellitus (ICI-induced DM) due to pembrolizumab. The patient has clinically improved and pembrolizumab was continued. The aim of this report is to highlight the importance of recognising ICI-induced DM as a rare immune-related adverse event in patients receiving programmed cell death protein 1/programmed cell death protein-ligand 1 inhibitor therapy and provide clinicians with insight into immune checkpoint endocrinopathies with an emphasis on diabetes and DKA.

Endocrine toxicity of cancer immunotherapy: clinical challenges

Immune checkpoint inhibitors are now widely used in the treatment of multiple cancers. The major toxicities of these treatments are termed immune-related adverse events and endocrine dysfunction is common. Thyroid disease, hypopituitarism and a form of diabetes resembling type 1 diabetes are now all well described, with different patterns emerging with different checkpoint inhibitors. We review the presentation and management of the common endocrine immune-related adverse events, and discuss a number of recent advances in the understanding of these important, potentially life threatening toxicities. We also discuss some remaining dilemmas in management.

Harnessing CD8+ T-cell exhaustion to treat type 1 diabetes

Although immune interventions have shown great promise in type 1 diabetes mellitus (T1D) clinical trials, none are yet in routine clinical use or able to achieve insulin independence in patients. In addition to this, the principles of T1D treatment remain essentially unchanged since the isolation of insulin, almost a century ago. T1D is characterized by insulin deficiency as a result of destruction of insulin-producing beta cells mediated by autoreactive T cells. Therapies that target beta-cell antigen-specific T cells are needed to prevent T1D. CD8⁺ T-cell exhaustion is an emerging area of research in chronic infection, cancer immunotherapy, and more recently, autoimmunity. Recent data suggest that exhausted T-cell populations are associated with improved markers of T1D. T-cell exhaustion is both characterized and mediated by inhibitory receptors. This review aims to identify which inhibitory receptors may prove useful to induce T-cell exhaustion to treat T1D and identify limitations and gaps in the current literature.

Diabetes mellitus induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are widely used in oncology for their favourable antitumor efficacy. ICI therapy is associated with a unique toxicity profile known as immune-related adverse events (irAEs). One such irAE is ICI-related diabetes mellitus (DM), which is relatively uncommon but can become extremely severe, leading to irreversible impairment of β-cells, and even lead to death if not promptly recognised and properly managed. The precise mechanisms of ICI-related DM are not well understood. In this review, we summarise the clinical characteristics, pathophysiology, and management of this adverse effect caused by ICI therapy. Deeper investigation of ICI-related DM may contribute to elucidate the molecular mechanisms of classical type 1 DM.

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.

Immune checkpoint inhibitor diabetes mellitus: a novel form of autoimmune diabetes

Autoimmune diabetes mellitus is a rare but significant side effect of treatment with immune checkpoint inhibitors. Immune checkpoint inhibitor-induced diabetes mellitus (CPI-DM) is characterized by acute onset of dramatic hyperglycemia with severe insulin deficiency and occurrence following exposure to programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors rather than cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) inhibitors. As a growing number of patients undergo immunotherapy, further understanding of the characteristics of CPI-DM patients is needed for improved prognostic and diagnostic application in order to reduce overall morbidity for this already at-risk population. Additionally, understanding of the features and mechanisms of CPI-DM may contribute to understanding mechanisms of spontaneous type I diabetes mellitus (T1DM). Here, we summarize the clinical features of CPI-DM and interrogate the genetic and cellular mechanisms that may contribute to the disease, as well as the clinical challenges for predicting and treating these patients as increasing cancer immunotherapies reach clinical utility.

Non-insulin-dependent Diabetes Mellitus Induced by Immune Checkpoint Inhibitor Therapy in an Insulinoma-associated Antigen-2 Autoantibody-positive Patient with Advanced Gastric Cancer

A 70-year-old man with insulinoma-associated antigen-2 autoantibodies developed diabetes mellitus (DM) without ketoacidosis after starting nivolumab to treat advanced gastric cancer. He subsequently exhibited preserved insulin-secretion capacity for over one year. Immune checkpoint inhibitors (ICIs) infrequently cause type 1 DM associated with the rapid loss of insulin secretion and ketoacidosis as an immune-related adverse event. ICIs may also cause non-insulin-dependent DM by inducing insulin resistance if there is islet autoantibody-related latent beta-cell dysfunction. The present case highlights the importance of testing blood glucose levels regularly to diagnose DM in patients treated with ICIs, even if they do not have diabetic ketoacidosis.

Immunotherapy-induced endocrinopathies: assessment, management and monitoring

Immunotherapy with checkpoint inhibitors has transformed the treatment of cancer, but frequently results in immune-mediated adverse events affecting multiple organs, amongst which endocrine adverse events are frequent. The patterns of endocrine adverse events differ between inhibitors of the CTLA-4 and PD-1/PD-L1 pathways, but most frequently involve the thyroid and pituitary with insulin deficient diabetes also emerging as an important adverse event. These frequently result in long-lasting hormone deficiency requiring replacement. This review explores the mechanism of action of checkpoint inhibitors and details the expected endocrine adverse events and typical presentations. The effect of high-dose glucocorticoids therapy to treat nonendocrine adverse events is also discussed.

Immune checkpoint inhibitors and type 1 diabetes mellitus: a case report and systematic review

OBJECTIVE

To better define the rare adverse event (AE) of diabetes mellitus associated with immune checkpoint inhibitors (ICIs).

DESIGN AND METHODS

We report the case of a lung cancer patient with diabetic ketoacidosis (DKA) and autoimmune thyroiditis during pembrolizumab treatment. We provide a systematic review of all published cases (PubMed/Web of Science/Cochrane, through November 2018) of autoimmune diabetes mellitus related to blockade of the cytotoxic T-lymphocyte antigen 4 (CTLA-4)-, programmed cell death 1 (PD-1) receptor or its ligand (PD-L1) or combination (ICI) therapy.

RESULTS

Our literature search identified 90 patient cases (our case excluded). Most patients were treated with anti-PD-1 or anti-PD-L1 as monotherapy (79%) or in combination with CTLA-4 blockade (15%). On average, diabetes mellitus was diagnosed after 4.5 cycles; earlier for combination ICI at 2.7 cycles. Early-onset diabetes mellitus (after one or two cycles) was observed during all treatment regimens. Diabetic ketoacidosis was present in 71%, while elevated lipase levels were detected in 52% (13/25). Islet autoantibodies were positive in 53% of patients with a predominance of glutamic acid decarboxylase antibodies. Susceptible HLA genotypes were present in 65% (mostly DR4). Thyroid dysfunction was the most frequent other endocrine AE at 24% incidence in this patient population.

CONCLUSION

ICI-related diabetes mellitus is a rare but often life-threatening metabolic urgency of which health-care professionals and patients should be aware. Close monitoring of blood glucose and prompt endocrine investigation in case of hyperglycemia is advisable. Predisposing factors such as HLA genotype might explain why some individuals are at risk.

Challenges in the management of people with diabetes and cancer

Although micro- and macrovascular complications of diabetes are the most important cause of mortality and morbidity in people with diabetes, it is increasingly recognized that diabetes increases the risk of developing cancer. Diabetes and cancer commonly co-exist, and outcomes in people with both conditions are poorer than in those who have cancer but no diabetes. There is no randomized trial evidence that treating hyperglycaemia in people with cancer improves outcomes, but therapeutic nihilism should be avoided, and a personalized approach to managing hyperglycaemia in people with cancer is needed. This review aims to outline the link between diabetes therapies and cancer, and discuss the reasons why glucose should be actively managed people with both. In addition, we discuss clinical challenges in the management of hyperglycaemia in cancer, specifically in relation to glucocorticoids, enteral feeding and end-of-life care.

A case of pembrolizumab-induced severe DKA and hypothyroidism in a patient with metastatic melanoma

Immune checkpoint inhibitors (ICIs) have revolutionised cancer therapy and improved outcomes for patients with advanced disease. Pembrolizumab, a monoclonal antibody that acts as a programmed cell death 1 (PD-1(PDCD1)) inhibitor, has been approved for the treatment of advanced melanoma and other solid tumours. Immune-related adverse events (irAEs) including endocrinopathies have been well described with this and other PD-1 inhibitors. While hypothyroidism and hyperthyroidism, and less commonly hypophysitis, are the most common endocrinopathies occurring in patients treated with pembrolizumab, the incidence of type 1 diabetes mellitus (T1DM) was low in clinical trials. We report a case of pembrolizumab-induced primary hypothyroidism and T1DM presenting with severe diabetic ketoacidosis (DKA). A 52-year-old male patient was treated with pembrolizumab for metastatic melanoma. He presented to the emergency department with a 1-day history of nausea and vomiting 2 weeks after his seventh dose of pembrolizumab, having complained of polyuria and polydipsia for 2 months before presentation. He had been diagnosed with thyroid peroxidase (TPO) antibody-negative hypothyroidism, requiring thyroxine replacement, shortly after his fifth dose. Testing revealed a severe DKA (pH: 6.99, glucose: 38.6 mmol/L, capillary ketones: 4.9 and anion gap: 34.7). He was treated in the intensive care unit as per the institutional protocol, and subsequently transitioned to subcutaneous basal-bolus insulin. After his diabetes and thyroid stabilised, pembrolizumab was recommenced to treat his advanced melanoma given his excellent response. This case highlights the importance of blood glucose monitoring as an integral part of cancer treatment protocols composed of pembrolizumab and other ICIs. Learning points: The incidence of T1DM with pembrolizumab treatment is being increasingly recognised and reported, and DKA is a common initial presentation. Physicians should counsel patients about this potential irAE and educate them about the symptoms of hyperglycaemia and DKA. The ESMO guidelines recommend regular monitoring of blood glucose in patients treated with ICIs, a recommendation needs to be incorporated into cancer treatment protocols for pembrolizumab and other ICIs in order to detect hyperglycaemia early and prevent DKA.