Blockade of the programmed death-1 (PD1) pathway undermines potent genetic protection from type 1 diabetes

Immune Checkpoint Inhibitors-Associated Diabetes and Ketoacidosis Were Found in FDA Adverse Event Reporting System: A Real-World Evidence Database Study

OBJECTIVE

To investigate the risk of developing diabetes and ketoacidosis in clinical patients with immune checkpoint inhibitors (ICIs).

METHODS

We looked in the FDA Adverse Event Reporting System for reports of ICIs-associated diabetes mellitus (DM) and ketoacidosis between January 2004 and March 2022. We explored the signals using fourfold table-based proportional imbalance algorithms. Patient characteristics, country distribution, and outcomes of adverse reactions were described. Kruskal-Wallis test was used to compare the time of onset and prognosis of adverse reactions.

RESULTS

A total of 2110 reports of ICIs-related DM were included in the study. The largest number of reports was from Japan (752, 35.64%), followed by the United States and France (624, 29.57%; 183, 8.67%). Seven drugs detected signals of DM and ketoacidosis according to 4 proportional imbalance algorithms: nivolumab, pembrolizumab, cemiplimab, dostarlimab, atezolizumab, avelumab, and durvalumab. Diabetes and ketoacidosis generally occurred early in the course of ICIs treatment, the median time to event onset was 144.5 (interquartile range 27-199) days. ICIs-related diabetes and ketoacidosis events resulted in 934 major medical events (44.3%), 524 hospitalizations (24.8%), 60 life-threatening events (2.8%), 42 deaths (2.0%), and 39 disability events (1.8%).

CONCLUSION

The study reveals the risk and characteristics of diabetes and ketoacidosis associated with ICIs, which may provide evidence for postmarketing evaluation. Careful consideration should be given to the possibility of an increased risk of diabetes and ketoacidosis after using ICIs, and careful monitoring for diabetes and ketoacidosis is recommended.

Endocrinopathies Associated With Immune Checkpoint Inhibitor Use

OBJECTIVE

To provide a clinical approach towards immune checkpoint inhibitor (ICI)-associated endocrinopathies, their link with cancer outcomes, factors which differentiate them from other immune related adverse events, and health systems innovation to improve care for these patients.

METHODS

A literature search for articles pertaining to ICIs and endocrinopathies was performed and supplemented by expert opinions of the authors.

RESULTS

While immune related adverse events can affect almost any organ, they frequently target the endocrine glands, most commonly thyroid. Different classes of ICIs have varying frequencies of endocrinopathies related to hypophysitis, thyroiditis, diabetes mellitus, and rarely hypoadrenalism and hypoparathyroidism. ICI-associated endocrinopathies share some features with classic endocrine autoimmunity but appear to be a distinct entity. They can be challenging to diagnose and manage due to nonspecific clinical features, use of exogenous glucocorticoids, and at times rapid and severe hormone deficiency. The role of anti-inflammatory high-dose glucocorticoids is minimal, and the ICI does not usually require permanent discontinuation. ICI-associated endocrinopathies usually cause permanent hormone deficiency necessitating long-term management and patient engagement. ICI-thyroiditis has been associated with improved survival, while other endocrinopathies have not shown a significant association with outcomes in cancer patients receiving ICIs. Oncoendocrinology teams can improve the care of patients with ICI-associated endocrinopathies.

CONCLUSION

This narrative review provides guidance to clinicians prescribing ICIs and those managing ICI-associated endocrinopathies, and complements the frameworks provided by major scientific societies in this field.

Murine MHC-Deficient Nonobese Diabetic Mice Carrying Human HLA-DQ8 Develop Severe Myocarditis and Myositis in Response to Anti-PD-1 Immune Checkpoint Inhibitor Cancer Therapy

Myocarditis has emerged as an immune-related adverse event of immune checkpoint inhibitor (ICI) cancer therapy associated with significant mortality. To ensure patients continue to safely benefit from life-saving cancer therapy, an understanding of fundamental immunological phenomena underlying ICI myocarditis is essential. We recently developed the NOD-cMHCI/II-/-.DQ8 mouse model that spontaneously develops myocarditis with lower mortality than observed in previous HLA-DQ8 NOD mouse strains. Our strain was rendered murine MHC class I and II deficient using CRISPR/Cas9 technology, making it a genetically clean platform for dissecting CD4+ T cell-mediated myocarditis in the absence of classically selected CD8+ T cells. These mice are highly susceptible to myocarditis and acute heart failure following anti-PD-1 ICI-induced treatment. Additionally, anti-PD-1 administration accelerates skeletal muscle myositis. Using histology, flow cytometry, adoptive transfers, and RNA sequencing analyses, we performed a thorough characterization of cardiac and skeletal muscle T cells, identifying shared and unique characteristics of both populations. Taken together, this report details a mouse model with features of a rare, but highly lethal clinical presentation of overlapping myocarditis and myositis following ICI therapy. This study sheds light on underlying immunological mechanisms in ICI myocarditis and provides the basis for further detailed analyses of diagnostic and therapeutic strategies.

Successful treatment of nivolumab and ipilimumab triggered type 1 diabetes by using sodium-glucose transporter 2 inhibitor: a case report and systematic review

Objective

Checkpoint inhibitors (CPIs) can trigger complications related to the autoimmune process such as CPI-triggered diabetes mellitus. The typical treatment for CPI-triggered diabetes is insulin, but a detailed therapeutic method has not yet been established. To prevent severe symptoms and mortality of diabetic ketoacidosis in advanced-stage cancer patients, the establishment of effective treatment of CPI-triggered diabetes, other than insulin therapy, is required.

Methods

We present a case of a 76-year-old man with CPI-triggered diabetes who was treated with nivolumab and ipilimumab for lung cancer. We also conducted a systematic review of 48 case reports of type 1 diabetes associated with nivolumab and ipilimumab therapy before June 2023.

Results

The patient's hyperglycemia was not sufficiently controlled by insulin therapy, and after the remission of ketoacidosis, the addition of a sodium-glucose transporter (SGLT) 2 inhibitor, dapagliflozin, improved glycemic control. Most of the reported nivolumab/ipilimumab-induced type 1 diabetes was treatable with insulin, but very few cases required additional oral anti-diabetic agents to obtain good glucose control.

Conclusion

Although SGLT2 inhibitors have been reported to have adverse effects on ketoacidosis, recent studies indicate that the occurrence of ketoacidosis is relatively rare. Considering the pathological mechanism of CPI-triggered diabetes, SGLT2 inhibitors could be an effective choice if they are administered while carefully monitoring the patient's ketoacidosis.

Structure of PD1 and its mechanism in the treatment of autoimmune diseases

PD-1 and CTLA-4 can play an important role in addressing the issue of autoimmune diseases. PD-1 is a transmembrane glycoprotein expressed on T, B, and Dentric cells. This molecule functions as a checkpoint in T cell proliferation. Ligation of PD-1 with its ligands inhibits the production of IL-2, IL-7, IL-10, and IL-12 as well as other cytokines by macrophages, natural killer (NK) cells, and T cells, which can suppress cell proliferation and inflammation. Today, scientists attempt to protect against autoimmune diseases by PD-1 inhibitory signals. In this review, we discuss the structure, expression, and signaling pathway of PD-1. In addition, we discuss the importance of PD-1 in regulating several autoimmune diseases, reflecting how manipulating this molecule can be an effective method in the immunotherapy of some autoimmune diseases.

Stocking the toolbox-Using preclinical models to understand the development and treatment of immune checkpoint inhibitor-induced immune-related adverse events

Cancer patients treated with immune checkpoint inhibitors (ICIs) are susceptible to a broad and variable array of immune-related adverse events (irAEs). With increasing clinical use of ICIs, defining the mechanism for irAE development is more critical than ever. However, it currently remains challenging to predict when these irAEs occur and which organ may be affected, and for many of the more severe irAEs, inaccessibility to the tissue site hampers mechanistic insight. This lack of understanding of irAE development in the clinical setting emphasizes the need for greater use of preclinical models that allow for improved prediction of biomarkers for ICI-initiated irAEs or that validate treatment options that inhibit irAEs without hampering the anti-tumor immune response. Here, we discuss the utility of preclinical models, ranging from exploring databases to in vivo animal models, focusing on where they are most useful and where they could be improved.

Clinical and HLA genotype analysis of immune checkpoint inhibitor-associated diabetes mellitus: a single-center case series from China

Objective

To investigate the clinical characteristics and HLA genotypes of patients with immune checkpoint inhibitor-associated diabetes mellitus (ICI-DM) in China.

Methods

We enrolled 23 patients with ICI-DM and 51 patients with type 1 diabetes (T1D). Clinical characteristics of the patients were collected. HLA-DRB1, HLA-DQA1, and HLA-DQB1 genotyping was conducted via next-generation sequencing.

Results

The ICI-DM patients had a male predominance (70.6%), a mean body mass index (BMI) of 21.2 ± 3.5 kg/m², and a mean onset of ICI-DM in 5 (IQR, 3-9) cycles after ICI therapy. Most (78.3%) ICI-DM patients were treated with anti-PD-1, 78.3% presented with diabetic ketoacidosis, and all had low C-peptide levels and received multiple insulin injections. Compared to T1D patients, ICI-DM patients were significantly older (57.2 ± 12.4 vs 34.1 ± 15.7 years) and had higher blood glucose but lower HbA1c levels (P<0.05). Only two (8.7%) ICI-DM patients were positive for islet autoantibodies, which was lower than that in T1D patients (66.7%, P<0.001). A total of 59.1% (13/22) of ICI-DM patients were heterozygous for an HLA T1D risk haplotype, and DRB1*0901-DQA1*03-DQB1*0303 (DR9) and DRB1*0405-DQA1*03-DQB1*0401 were the major susceptible haplotypes. Compared to T1D, the susceptible DR3-DQA1*0501-DQB1*0201 (DR3) and DR9 haplotypes were less frequent (17.7% vs 2.3%; P=0.011 and 34.4% vs 15.9%; P=0.025), whereas the protective haplotypes (DRB1*1101-DQA1*05-DQB1*0301 and DRB1*1202-DQA1*0601-DQB1*0301) were more frequent in ICI-DM patients (2.1% vs 13.6%; P=0.006 and 4.2% vs 15.9%; P=0.017). None of the ICI-DM patients had T1D-associated high-risk genotypes DR3/DR3, DR3/DR9, and DR9/DR9. Among the 23 ICI-DM patients, 7 (30.4%) presented with ICI-associated fulminant type 1 diabetes (IFD), and 16 (69.6%) presented with ICI-associated type 1 diabetes (IT1D). Compared to IT1D patients, IFD patients exhibited marked hyperglycemia and low C-peptide and HbA1c levels (P<0.05). Up to 66.7% (4/6) of IFD patients were heterozygous for reported fulminant type 1 diabetes susceptibility HLA haplotypes (DRB1*0405-DQB1*0401 or DRB1*0901-DQB1*0303).

Conclusion

ICI-DM shares similar clinical features with T1D, such as acute onset, poor islet function and insulin dependence. However, the lack of islet autoantibodies, the low frequencies of T1D susceptibility and high frequencies of protective HLA haplotypes indicate that ICI-DM represents a new model distinct from classical T1D.

Characterization of immune checkpoint inhibitor-associated fulminant type 1 diabetes associated with autoantibody status and ethnic origin

OBJECTIVE

Fulminant type 1 diabetes may uniquely occur as a fatal adverse event during immune checkpoint inhibitor (ICI) therapy. We investigated the clinical and immunological characteristics of ICI-associated fulminant type 1 diabetes (IFD).

RESEARCH DESIGN AND METHODS

We enrolled 80 patients with IFD (77 cases from the literature), 56 patients with ICI-associated type 1 diabetes (IT1D) (55 cases from the literature), 45 patients with traditional fulminant type 1 diabetes (TFD), and 43 patients with acute-onset type 1 diabetes for comprehensive analysis including islet autoantibodies and subgroup analysis based on ethnic origin.

RESULTS

Patients with IFD accounted for 58.8% (80/136) of patients with ICI-related diabetes. IFD had a more rapid onset than IT1D after ICI therapy (90.5 days vs. 120 days, p <0.05). The onset time and number of infusions after ICI therapy initiation were lower in the antibody-positive IFD group than that in the antibody-negative IFD group (both p <0.001). IFD had a more rapid onset and more serious among Caucasians than that among Asians (p <0.01, p <0.05, respectively), and the prevalence of islet autoantibody positivity in the Caucasian IFD were prominently higher than those in the Asian IFD (p <0.05). Onset age and plasma glucose levels were significantly higher in the IFD group than those in the TFD and acute-onset type 1 diabetes groups. HbA1c levels were slightly higher in patients with IFD than those with TFD.

CONCLUSIONS

IFD is relatively common in Caucasian population where TFD is very rare or almost absent. IFD occurrence is significantly related to islet autoantibody status and ethnic origin.

Immune cells and their inflammatory mediators modify β cells and cause checkpoint inhibitor-induced diabetes

Checkpoint inhibitors (CPIs) targeting programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) have revolutionized cancer treatment but can trigger autoimmune complications, including CPI-induced diabetes mellitus (CPI-DM), which occurs preferentially with PD-1 blockade. We found evidence of pancreatic inflammation in patients with CPI-DM with shrinkage of pancreases, increased pancreatic enzymes, and in a case from a patient who died with CPI-DM, peri-islet lymphocytic infiltration. In the NOD mouse model, anti-PD-L1 but not anti-CTLA-4 induced diabetes rapidly. RNA sequencing revealed that cytolytic IFN-γ+CD8+ T cells infiltrated islets with anti-PD-L1. Changes in β cells were predominantly driven by IFN-γ and TNF-α and included induction of a potentially novel β cell population with transcriptional changes suggesting dedifferentiation. IFN-γ increased checkpoint ligand expression and activated apoptosis pathways in human β cells in vitro. Treatment with anti-IFN-γ and anti-TNF-α prevented CPI-DM in anti-PD-L1-treated NOD mice. CPIs targeting the PD-1/PD-L1 pathway resulted in transcriptional changes in β cells and immune infiltrates that may lead to the development of diabetes. Inhibition of inflammatory cytokines can prevent CPI-DM, suggesting a strategy for clinical application to prevent this complication.

New-onset type 1 diabetes mellitus as a delayed immune-related event after discontinuation of nivolumab: A case report

RATIONALE

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, they may cause immune-related adverse events. Although there have been a few reports of new-onset type 1 diabetes mellitus (T1DM) during ICI treatment, T1DM as a delayed immune-related event after discontinuing immunotherapy is extremely rare. Herein, we report the case of an elderly veteran who presented with diabetic ketoacidosis 4 months after the discontinuation of treatment with nivolumab.

PATIENT CONCERNS

A 74-year-old veteran was treated with second-line nivolumab for advanced non-small cell lung cancer. After 9 treatment cycles, the administration was discontinued due to fatigue. Four months later, he was admitted to the emergency department in a stuporous mental state and hyperglycemia, with high glycosylated hemoglobin levels (10.6%). C-peptide levels were significantly decreased, with negative islet autoantibodies.

DIAGNOSES

We diagnosed nivolumab-induced T1DM. There were no laboratory results indicating a new thyroid dysfunction or adrenal insufficiency, which are typical endocrine adverse reactions.

INTERVENTIONS

Since the hypothalamic and pituitary functions were preserved and only the pancreatic endocrine capacity was impaired, we administered continuous intravenous insulin injections, with fluid and electrolyte replacement.

OUTCOMES

His serum glucose levels decreased, and symptoms improved; hence, on the 8 day of hospitalization, we switched to multiple daily insulin injections.

LESSONS

The present case indicates that regular glucose monitoring and patient education are needed for diabetic ketoacidosis after the discontinuation of ICI therapy.

PD-1 inhibitor-associated type 1 diabetes: A case report and systematic review

Objective

This study aimed to summarize the clinical characteristics of programmed death receptor 1 (PD-1) inhibitor-associated type 1 diabetes so as to improve the ability of clinicians to correctly diagnose and treat it.

Methods

We reported a case of a 70-year-old woman with gastric cancer who developed hyperosmolar hyperglycemic coma during camrelizumab (a PD-1 inhibitor) treatment and was diagnosed with PD-1 inhibitor-associated type 1 diabetes. We conducted a systematic review of 74 case reports of type 1 diabetes associated with PD-1 inhibitor therapy published before June 2022.

Results

The patient developed type 1 diabetes with hyperosmolar hyperglycemic coma after receiving camrelizumab chemotherapy for 6 months (9 cycles). We searched 69 English articles comprising 75 patients, all of whom had been treated with a PD-1 inhibitor (nivolumab or pembrolizumab) and progressed to diabetes after an average of 6.11 (1–28) cycles. Nivolumab combined with ipilimumab (a cytotoxic T lymphocyte-associated protein 4 inhibitor) had the shortest onset (4.47 cycles on average). A total of 76% (57/75) of patients developed diabetic ketoacidosis (DKA) at onset, and 50.67% (38/75) of patients had C-peptide <0.1 ng/mL. Most of the patients were tested for insulin autoantibodies, with a positive rate of 33.33% (23/69); of these, 86.96% (20/23) were tested for glutamate decarboxylase antibody and 46.67% (35/75) were tested for human leukocyte antigen (HLA). HLA-DR4 was the most common type.

Conclusions

The progression of type 1 diabetes induced by PD-1 inhibitors is relatively rapid. Islet failure often occurs when detected, seriously endangering patients' lives. Patients treated with PD-1 inhibitors should closely monitor their plasma glucose level during treatment to detect, diagnose, and treat diabetes on time.

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.

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.

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

Immune checkpoint inhibitors (ICIs) are a relatively newer class of drugs approved for the treatment of malignancies such as melanoma, renal, bladder and lung cancer. Immune-related adverse events (IrAEs) involving the endocrine system are a common side effect of these drugs. The spectrum of endocrine adverse events varies by the drug class. Cytotoxic T-lymphocyte–associated antigen-4 inhibitors commonly cause hypophysitis/hypopituitarism, whereas the incidence of thyroid disease is higher with programmed cell death (PD)-1/ ligand (PD-L) protein 1 inhibitors. The focus of this review is to describe the individual endocrinopathies with their possible mechanisms, signs and symptoms, clinical assessment and disease management. Multiple mechanisms of IrAEs have been described in literature including type II/IV hypersensitivity reactions and development of autoantibodies. Patients with pre-existing autoimmune endocrine diseases can have disease exacerbation following ICI therapy rather than de novo IrAEs. Most of the endocrinopathies are relatively mild, and timely hormone replacement therapy allows continuation of ICIs. However, involvement of the pituitary–adrenal axis could be life-threatening if not recognized. Corticosteroids are helpful when the pituitary–adrenal axis is involved. In cases of severe endocrine toxicity (grade 3/4), ICIs should be temporarily discontinued and can be restarted after adequate hormonal therapy. Endocrinologists and general internists need to be vigilant and maintain a high degree of awareness for these adverse events.

Immunotherapy-Associated Pancreatic Adverse Events: Current Understanding of Their Mechanism, Diagnosis, and Management

Immune checkpoint inhibitors (ICIs) such as anti-programmed death-1 (PD-1) and its ligand PD-L1 and anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) monoclonal antibodies, are involved in T cell-mediated immune response augmentation and promote anti-tumor immunity. Cancer patients treated with combination of immunotherapy, chemotherapy, radiotherapy, and targeted therapy exhibit superior clinical outcomes and tolerance compared with patients treated with monotherapies. However, immutherapy is associated with several concomitant immune-related adverse events (irAEs). For instance, IrAEs interferes with function of gastrointestinal tract, endocrine, dermatological, nervous system and musculoskeletal systems. ICIs-associated pancreatic injury might causes decrease in endocrine and exocrine pancreatic function, resulting in metabolic and nutritional disorders. Clinicians who administer immune checkpoint inhibitors to cancer patients are diagnosed with hyperglycemia, abdominal pain and steatorrhea. Currently, the precise mechanism of ICIs-associated pancreatic injury has not been fully explored. This paper summarizes incidence, diagnosis, clinical characteristics, potential mechanisms, and treatment management patterns of ICIs-associated pancreatic AEs based on previous studies. In addition, possible management approaches of these adverse effects are presented in this paper. in the findings summarized in this paper lay a basis for management of ICIs-associated pancreatic AEs and expanding future immunotherapy applications.

A novel mouse model for checkpoint inhibitor-induced adverse events

Immune checkpoint inhibitors have demonstrated significant efficacy in the treatment of a variety of cancers, however their therapeutic potential is limited by abstruse immune related adverse events. Currently, no robust animal model exists of checkpoint inhibitor-induced adverse events. Establishing such a model will improve our mechanistic understanding of this process, which in turn will inform design of improved therapies. We developed a mouse model to determine inflammatory toxicities in response to dual checkpoint blockade in the presence of syngeneic tumors. Mice from susceptible genetic backgrounds received intraperitoneal injections of anti-mouse PD-1 and CTLA-4 antibodies. The mice were monitored for weight loss and histologic evidence of inflammation. Blood was collected for basic metabolic panels and titers of anti-nuclear antibodies. In parallel, mice were also treated with prednisolone, which is commonly used to treat immune related adverse events among cancer patients. Among all the genetic backgrounds, B6/lpr mice treated with anti-CTLA-4 and anti-PD-1 antibodies developed more substantial hepatitis, pancreatitis, colitis, and pneumonitis characterized by organ infiltration of immune cells. Mice that developed tissue infiltration demonstrated high serum levels of glucose and high titers of anti-nuclear antibodies. Finally, while administration of prednisolone prevented the development of the inflammatory adverse events, it also abrogated the protective anti-tumor effect of the checkout inhibitors. Genetic background and treatment modalities jointly modified the inflammatory adverse events in tumor bearing mice, suggesting a complex mechanism for checkpoint inhibitor-related inflammation. Future studies will assess additional genetic susceptibility factors and will examine possible contributions from the administration of other anti-inflammatory drugs.

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.

New onset diabetes with ketoacidosis following nivolumab immunotherapy: A case report and review of literature

Introduction

Immune-checkpoint inhibitors have become an increasingly popular form of systemic therapy for cancer treatment. Their use has proven to be so effective that certain regimens have gained approval as first-line therapy for various solid tumor types. The most common and well-studied forms of immunotherapy include agents that target cytotoxic T-lymphocyte antigen-4, programmed death-1, and programmed death ligand-1. These therapies act by blocking signaling between immune cells and cancer cells which subsequently augment T cell-mediated destruction of tumor cells.

Case report

Here, we report a case of a 77-year-old black male with no history of or risk factors for diabetes mellitus who presented with acute onset of diabetic ketoacidosis after beginning immunotherapy with nivolumab for metastatic high-grade neuroendocrine tumor of the lung. He was admitted and treated for diabetic ketoacidosis but required prolonged use of an insulin infusion with frequent need of intravenous dextrose due to labile blood sugars. The patient was eventually discharged and discontinued further immunotherapy with nivolumab.

Discussion

Due to the unique mechanisms by which immune-checkpoint inhibitors cause immune-mediated destruction of tumor cells, clinicians may be challenged with their associated autoimmune complications referred to as immune-related adverse events. In particular, the incidence of endocrine dysfunction following immune-checkpoint inhibitor therapy is approximately 12%, with the development of insulin-dependent diabetes mellitus being a rare complication. Increasing awareness of immune-related adverse events is essential for the early recognition and effective management of patients who present with life-threatening complications related to immune-checkpoint inhibitor therapy.

Cases from the Immune-Related Adverse Event Tumor Board: Diagnosis and Management of Immune Checkpoint Blockade-Induced Diabetes

The addition of immune checkpoint inhibitors to the armamentarium of cancer therapies has resulted in unprecedented improvement in clinical outcomes for a vast range of malignancies. Because they interfere with the physiologic function of immune checkpoints, such as programmed cell death protein 1 or cytotoxic T-lymphocyte-associated protein 4, to promote self-tolerance, these agents are associated with a unique spectrum of immune-related adverse events (irAEs). Immune-mediated endocrinopathies are among the most commonly noted irAEs. Immune-mediated diabetes is an uncommon irAE but can be associated with significant morbidity if it is not recognized and treated in a time-sensitive manner. In this manuscript, we present a case based discussion and review of the literature pertaining to immune-mediated diabetes associated with immune checkpoint blockade. KEY POINTS: Immune checkpoint inhibitor associated diabetes mellitus often resembles type 1 diabetes mellitus (DM) in its pathophysiology and clinical manifestations. However, some patients may present with type 2 DM or worsening hyperglycemia in the setting of pre-existent DM. Early recognition and management is key to preventing life-threatening events such as diabetic ketoacidosis. Endocrinology referral and interdisciplinary management should be considered for every patient to optimize glycemic control and to ensure optimal monitoring for long-term microvascular complications.

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.

Diabetes and Blood Glucose Disorders Under Anti-PD1

Acute type 1 diabetes (AD1) is a rare but definitive immune-related adverse event associated with anti-PD1. Most of the reported cases are close to what has been described as "fulminant type 1 diabetes." We sought to determine whether anti-PD1 could impair glycoregulation and whether occurrence of AD1 could be anticipated by prior glycemic changes. Fasting glycemia collected before, under, and after treatment in melanoma patients treated with anti-PD1 over a period of 36 months were retrospectively analyzed. Glycemic trend analyses were performed using linear regression analysis. In total, 1470 glucose values were monitored in 163 patients treated for a mean duration of 5.96 months. Three patients developed an AD1 (1, 84%). Two other cases were observed in the same period in a still-blinded trial of anti-PD1 versus ipilimumab. All cases of AD1 occurred in patients with a normal pretreatment glycemia, and there was no detectable drift of glycemia before ketoacidosis onset. In 4 of 5 cases of AD1, the HLA subgroups were DRB01* 03 or 04, known to increase type 1 diabetes risk in the general population. In the 28 patients with preexisting type 2 diabetes, there was a slight trend for glycemia increase with anti-PD1 infusions (0.05 mmol/L/infusion P=0.004). In the 132 patients with normal pretreatment glycemia, there was a slight trend for a decrease of glycemia with anti-PD1 infusions (-0.012/mmol/L/infusion P=0.026). These data suggest that the monitoring of glycemia under anti-PD1 cannot help to anticipate AD1, and there is no general tendency to glycemic disorder. HLA genotyping before treatment may help to focus surveillance in patients with the HLA DRB1*03/04 group.

The Inhibitory T Cell Receptors PD1 and 2B4 Are Differentially Regulated on CD4 and CD8 T Cells in a Mouse Model of Non-alcoholic Steatohepatitis

Infiltrating CD4 and CD8 T cells have been shown to worsen inflammatory liver damage in non-alcoholic steatohepatitis (NASH). Inhibitory T cell receptors such as the programmed cell death protein 1 (PD1) and the natural killer cell receptor 2B4 regulate the activity of CD4 and CD8 T cells and therefore play an important role in immune tolerance required in the liver. In this study, we investigated the expression profile of inhibitory T cell receptors on CD4 and CD8 T cells in a mouse model of NASH. Male B57BL/6J mice were fed a Western diet for 24 weeks. The expression levels of inhibitory receptors on the surface of intrahepatic and peripheral T cells were measured and correlated with markers of activation (CD107a, CD69, and CD44), metabolic disorder (serum triglycerides, serum cholesterol, γ-glutamyl transferase, hepatic triglycerides), inflammation (serum alanine aminotransferase and aspartate aminotransferase) and hepatic fibrosis (collagen 1A1, α-smooth muscle actin, hydroxyproline). Under Western diet, PD1 is exclusively upregulated on intrahepatic and peripheral CD8⁺ T cells, whereas the expression level on CD4 T cells is unaffected. In contrast, 2B4 is upregulated liver-specifically on both CD4 and CD8 T cells and unchanged on peripheral T cells. Upregulation of PD1 on CD8 T cells is restricted to CD8 effector memory T cells and correlates with lower levels of degranulation. Similarly, the inhibitory function of PD1 on intrahepatic CD4 T cells is shown by a lower CD69 and CD44 expression on PD1-positive CD4 T cells. In murine steatohepatitis, the upregulation of PD1 on CD8 T cells and 2B4 on CD4 and CD8 T cells potentially limits T cell-mediated liver damage. Therefore, these inhibitory T cell receptors could serve as promising targets of immune-modulatory NASH therapy.

The Balancing Act between Cancer Immunity and Autoimmunity in Response to Immunotherapy

The explosion in novel cancer immunotherapies has resulted in extraordinary clinical successes in the treatment of multiple cancers. Checkpoint inhibitors (CPIs) that target negative regulatory molecules have become standard of care. However, with the growing use of CPIs, alone or in combination with chemotherapy, targeted therapies, or other immune modulators, a significant increase in immune-related adverse events (irAEs) has emerged. The wide-ranging and currently unpredictable spectrum of CPI-induced irAEs can lead to profound pathology and, in some cases, death. Growing evidence indicates that many irAEs are a consequence of a breakdown in self-tolerance, but the influence of genetics, the environment, and the mechanisms involved remains unclear. This review explores key questions in this emerging field, summarizing preclinical and clinical experiences with this new generation of cancer drugs, the growing understanding of the role of the immune response in mediating these toxicities, the relationship of CPI-induced autoimmunity to conventional autoimmune diseases, and insights into the mechanism of irAE development and treatment.

A comprehensive review on the role of co-signaling receptors and Treg homeostasis in autoimmunity and tumor immunity

The immune system ensures optimum T-effector (Teff) immune responses against invading microbes and tumor antigens while preventing inappropriate autoimmune responses against self-antigens with the help of T-regulatory (Treg) cells. Thus, Treg and Teff cells help maintain immune homeostasis through mutual regulation. While Tregs can contribute to tumor immune evasion by suppressing anti-tumor Teff response, loss of Treg function can result in Teff responses against self-antigens leading to autoimmune disease. Thus, loss of homeostatic balance between Teff/Treg cells is often associated with both cancer and autoimmunity. Co-stimulatory and co-inhibitory receptors, collectively known as co-signaling receptors, play an indispensable role in the regulation of Teff and Treg cell expansion and function and thus play critical roles in modulating autoimmune and anti-tumor immune responses. Over the past three decades, considerable efforts have been made to understand the biology of co-signaling receptors and their role in immune homeostasis. Mutations in co-inhibitory receptors such as CTLA4 and PD1 are associated with Treg dysfunction, and autoimmune diseases in mice and humans. On the other hand, growing tumors evade immune surveillance by exploiting co-inhibitory signaling through expression of CTLA4, PD1 and PDL-1. Immune checkpoint blockade (ICB) using anti-CTLA4 and anti-PD1 has drawn considerable attention towards co-signaling receptors in tumor immunology and created renewed interest in studying other co-signaling receptors, which until recently have not been as well studied. In addition to co-inhibitory receptors, co-stimulatory receptors like OX40, GITR and 4-1BB have also been widely implicated in immune homeostasis and T-cell stimulation, and use of agonistic antibodies against OX40, GITR and 4-1BB has been effective in causing tumor regression. Although ICB has seen unprecedented success in cancer treatment, autoimmune adverse events arising from ICB due to loss of Treg homeostasis poses a major obstacle. Herein, we comprehensively review the role of various co-stimulatory and co-inhibitory receptors in Treg biology and immune homeostasis, autoimmunity, and anti-tumor immunity. Furthermore, we discuss the autoimmune adverse events arising upon targeting these co-signaling receptors to augment anti-tumor immune responses.

Jagged1-expressing adenovirus-infected dendritic cells induce expansion of Foxp3+ regulatory T cells and alleviate T helper type 2-mediated allergic asthma in mice

Dendritic cells (DCs) are professional antigen-presenting cells that play a key role in directing T-cell responses. Regulatory T (Treg) cells possess an immunosuppressive ability to inhibit effector T-cell responses, and Notch ligand Jagged1 (Jag1) is implicated in Treg cell differentiation. In this study, we evaluated whether bone marrow-derived DCs genetically engineered to express Jag1 (Jag1-DCs) would affect the maturation and function of DCs in vitro and further investigated the immunoregulatory ability of Jag1-DCs to manipulate T helper type 2 (Th2) -mediated allergic asthma in mice. We produced Jag1-DCs by adenoviral transduction. Overexpression of Jag1 by ovalbumin (OVA) -stimulated Jag1-DCs exhibited increased expression of programmed cell death ligand 1 (PD-L1) and OX40L molecules. Subsequently, co-culture of these OVA-pulsed Jag1-DCs with allogeneic or syngeneic CD4⁺ T cells promoted the generation of Foxp3⁺ Treg cells, and blocking PD-L1 using specific antibodies partially reduced Treg cell expansion. Furthermore, adoptive transfer of OVA-pulsed Jag1-DCs to mice with OVA-induced asthma reduced allergen-specific immunoglobulin E production, airway hyperresponsiveness, airway inflammation, and secretion of Th2-type cytokines (interleukin-4, interleukin-5, and interleukin-13). Notably, an increased number of Foxp3⁺ Treg cells associated with enhanced levels of transforming growth factor-β production was observed in Jag1-DC-treated mice. These data indicate that transgenic expression of Jag1 by DCs promotes induction of Foxp3⁺ Treg cells, which ameliorated Th2-mediated allergic asthma in mice. Our study supports an attractive strategy to artificially generate immunoregulatory DCs and provides a novel approach for manipulating Th2 cell-driven deleterious immune diseases.

Programmed Cell Death-1 Inhibitor-Induced Type 1 Diabetes Mellitus

CONTEXT

Pembrolizumab (Keytruda; Merck Sharp & Dohme) is a humanized IgG4 monoclonal antibody used in cancer immunotherapy. It targets the programmed cell death-1 (PD-1) receptor, which is important in maintaining self-tolerance. However, immune checkpoint blockade is associated with a risk for immune-related adverse events (irAEs) potentially affecting the endocrine organs. Type 1 diabetes mellitus is a rare irAE of PD-1 inhibitors, occurring in 0.2% of cases.

EVIDENCE ACQUISITION

Systematic search of four databases (MEDLINE, Embase, Web of Science, and Cochrane Library) using the search terms "diabetes" or "ketoacidosis" and "pembrolizumab," "nivolumab," "PD-1 inhibitor," or "immunotherapy." Included were articles published in English between 1 January 2012 and 1 January 2018. The search was supplemented by bibliographic searches of the complete reference lists of all included papers.

EVIDENCE SYNTHESIS

We provide an overview of all published cases (n = 42) of PD-1 inhibitor-induced type 1 diabetes mellitus to date, including a well-characterized case of islet cell antibody and glutamic acid decarboxylase antibody-positive diabetes mellitus, in a patient with a diabetes-prone HLA genotype. She presented with diabetic ketoacidosis during pembrolizumab therapy for a metastatic uveal melanoma. Furthermore, we discuss potential pathogenic mechanisms, clinical presentation, prognostic markers (β-cell antibodies and HLA type), treatment, and a screening protocol.

CONCLUSIONS

Because the use of immunotherapy will increase, it is essential that all clinicians are aware of diabetic ketoacidosis as a rare and life-threatening side effect of immunotherapy. Blood glucose monitoring during anti-PD-1 therapy is necessary.

Occurrence of type 1 and type 2 diabetes in patients treated with immunotherapy (anti-PD-1 and/or anti-CTLA-4) for metastatic melanoma: a retrospective study

Anti-PD-1 and anti-CTLA-4 antibodies cause immune-related side effects such as autoimmune type 1 diabetes (T1D). It has also been suggested that by increasing TNF-α, IL-2 and IFN-γ production, anti-PD-1 and/or anti-CTLA-4 treatment could affect pancreatic beta cell function and insulin sensitivity. This study was based on a retrospective observational analysis from 2 July 2014 to 27 June 2016, which evaluated the occurrence of T1D and changes in glycemia and C-reactive protein (CRP) plasma concentrations in patients undergoing anti-PD-1 and/or anti-CTLA-4 treatment for melanoma at the Saint Louis Hospital. All cases of T1D that developed during immunotherapy registered in the French Pharmacovigilance Database (FPVD) were also considered. Among the 132 patients included, 3 cases of T1D occurred. For the remaining subjects, blood glucose was not significantly affected by anti-PD-1 treatment, but CRP levels (mg/l) significantly increased during anti-PD-1 treatment (p = 0.017). However, 1 case of type 2 diabetes (T2D) occurred (associated with a longer therapy duration). Moreover, glycemia of patients pretreated (n = 44) or concomitantly treated (n = 8) with anti-CTLA-4 tended to increase during anti-PD-1 therapy (p = 0.068). From the FPVD, we obtained 14 cases of T1D that occurred during immunotherapy and were primarily characterized by the rapidity and severity of onset. In conclusion, in addition to inducing this rare immune-related diabetes condition, anti-PD-1 treatment appears to increase CRP levels, a potential inflammatory trigger of insulin resistance, but without any short-term impact on blood glucose level.

Fulminant Type 1 Diabetes Mellitus Accompanied by Positive Conversion of Anti-insulin Antibody after the Administration of Anti-CTLA-4 Antibody Following the Discontinuation of Anti-PD-1 Antibody

An 80-year-old woman with malignant melanoma received 20 cycles of anti-programmed death 1 (PD-1) antibody (nivolumab) treatment and showed normal glucose tolerance. Three weeks after switching to anti-cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) antibody (ipilimumab), her plasma glucose level was elevated to 639 mg/dL, her HbA1c was 7.7%, and her fastening serum C-peptide immunoreactivity was undetectable. Anti-glutamic acid decarboxylase and insulinoma-associated protein-2 antibodies were negative. She was diagnosed with fulminant type 1 diabetes mellitus (F1DM). Remarkably, her anti-insulin antibody was positively converted, and her Sialylated Carbohydrate Antigen, Krebs von den Lungen-6 levels increased after ipilimumab therapy. She possessed F1DM-susceptible Human Leukocyte Antigen-DR4. A fluorescence activated cell sorting analysis showed an altered T-cell population. This case of F1DM highlights specific mechanisms underlying pancreatic beta cell immunity.

Case report: pembrolizumab-induced Type 1 diabetes in a patient with metastatic cholangiocarcinoma

BACKGROUND

Immune checkpoint inhibitors are novel cancer therapies associated with numerous autoimmune toxicities, some of which are only now being appreciated.

CASE PRESENTATION

A 67-year old female with metastatic cholangiocarcinoma and no prior history of diabetes was treated with leucovorin, fluorouracil, oxaliplatin and pembrolizumab. After eight cycles, she developed new onset type 1 diabetes mellitus with positive glutamic acid decarboxylase antibody titers. Conclusions: To our knowledge, this is the first reported case of PD-1 inhibitor associated Type 1 diabetes mellitus in a patient with cholangiocarcinoma and supports others' experiences that PD-1 inhibition can cause a spectrum of autoimmune adverse events that require clinical monitoring and periodic screenings.

Nivolumab-induced fulminant diabetic ketoacidosis followed by thyroiditis

Five days following the 3rd cycle of nivolumab, a monoclonal antibody, which acts as immune checkpoint inhibitor against the programmed cell death protein-1, for metastatic lung adenocarcinoma, a 56-year-old woman presented at the hospital critically ill. On admission, she had severe diabetic ketoacidosis (DKA), as evidenced by venous glucose of 47 mmol/L, blood ketones of 7.5 mmol/L, pH of 6.95 and bicarbonate of 6.6 mmol/L. She has had no personal or family history of diabetes mellitus (DM), while random venous glucose, measured 1 week prior to hospitalisation, was 6.1 mmol/L. On admission, her HbA1c was 8.2% and anti-GAD antibodies were 12 kIU/L (0–5 kU/L), while islet cell antibodies and serum C-peptide were undetectable. Nivolumab was recommenced without the development of other immune-mediated phenomena until 6 months later, when she developed hypothyroidism with TSH 18 U/L and low free T4. She remains insulin dependent and has required levothyroxine replacement, while she has maintained good radiological and clinical response to immunotherapy. This case is notable for the rapidity of onset and profound nature of DKA at presentation, which occurred two months following commencement of immunotherapy. Despite the association of nivolumab with immune-mediated endocrinopathies, only a very small number of patients developing type 1 DM has been reported to date. Patients should be closely monitored for hyperglycaemia and thyroid dysfunction prior to and periodically during immunotherapy.

Diabetic Ketoacidosis as an Immune-related Adverse Event from Pembrolizumab in Non-Small Cell Lung Cancer

Programmed cell death protein 1 pathway inhibitors are now routinely administered to patients with non-small cell lung cancer, and prompt recognition of immune-related adverse events is critical to managing serious drug toxicities. Here, we describe a 66-year-old man with no known history of diabetes who presented with diabetic ketoacidosis after receiving 3 doses of pembrolizumab for lung adenocarcinoma. Autoimmune diabetes is a rare but potentially life-threatening complication of programmed cell death protein 1 inhibitors.

Endocrine dysfunction induced by immune checkpoint inhibitors: Practical recommendations for diagnosis and clinical management

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy. However, because ICIs block coinhibitory molecules on T cells and other immune cells, unleashing them to mediate tumor cell killing, they also can disrupt the maintenance of immunological tolerance to self-antigens. Compared with chemotherapy, ICIs have a different toxicity profile, especially the occurrence of autoimmune-like manifestations against multiple organ systems, including endocrine glands, commonly referred to as immune-related adverse events. The aim of this review was to provide practical recommendations regarding the proper assessment and clinical management related to the new onset of endocrinopathies after the use of ICIs in patients with cancer. Cancer 2018;124:1111-21. © 2018 American Cancer Society.

Requirement for CD40/CD40L Interactions for Development of Autoimmunity Differs Depending on Specific Checkpoint and Costimulatory Pathways

CD40/CD40L interactions play a critical role in immunity and autoimmunity. In this study, we sought to understand the requirement for CD40 signaling in the programmed cell death-1 (PD-1) checkpoint and CD28 costimulatory pathways important for maintenance of peripheral tolerance. Blocking either pathway can result in loss of self-tolerance and development of autoimmunity. We found that primary Sjögren's syndrome (pSS) and autoimmune thyroid diseases (ATDs) that develop spontaneously in CD28-deficient IFN-γ-/- NOD.H-2h4 (CD28-/-) mice required CD40 signaling. Specifically, blockade of CD40L with the anti-CD40L mAb, MR1, inhibited autoantibody production and inflammation in thyroid and salivary gland target tissues. Unexpectedly, however, ATD and pSS in PD-1-deficient IFN-γ-/- NOD.H-2h4 (PD-1-/-) mice developed independently of CD40/CD40L interactions. Treatment with MR1 had no effect and even exacerbated disease development in pSS and ATD, respectively. Most interesting, anti-thyroglobulin and pSS-associated autoantibodies were increased following anti-CD40L treatment, even though MR1 effectively inhibited the spontaneous splenic germinal centers that form in PD-1-deficient mice. Importantly, blockade of the PD-1 pathway by administration of anti-PD-1 mAb in CD28-/- mice recapitulated the PD-1-/- phenotype, significantly impacting the ability of MR1 to suppress ATD and pSS in these mice. These results indicate that there can be different pathways and requirements to autoimmune pathogenesis depending on the availability of specific checkpoint and costimulatory receptors, and an intact PD-1 pathway is apparently required for inhibition of autoimmunity by anti-CD40L.

Anti-PD-L1 atezolizumab-Induced Autoimmune Diabetes: a Case Report and Review of the Literature

Programmed cell death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors trigger an immune-mediated anti-tumour response by promoting the activation of cytotoxic T lymphocytes. Although proven to be highly effective in the treatment of several malignancies they can induce significant immune-related adverse events (irAEs) including endocrinopathies, most commonly hypophysitis and thyroid dysfunction, and rarely autoimmune diabetes. Here we present the first case report of a patient with a primary diagnosis of urothelial cancer developing PD-L1 inhibitor-induced autoimmune diabetes. A euglycemic 57 year old male presented to clinic with dehydration after the fifth cycle of treatment with the novel PD-L1 inhibitor atezolizumab. Blood tests demonstrated rapid onset hyperglycaemia (BM 24 mmol/L), ketosis and a low C-peptide level (0.65 ng/mL) confirming the diagnosis of type 1 diabetes. He responded well to insulin therapy and was discharged with stable blood glucose levels. Due to the widening use of PD-1/PD-L1 inhibitors in cancer treatment clinicians need to be aware of this rare yet treatable irAE. Given the morbidity and mortality associated with undiagnosed autoimmune diabetes we recommend routine HbA1c and plasma glucose testing in all patients prior to and during treatment with PD-1/PD-L1 inhibitors until more evidence has accumulated on identifying those patients with a pre-treatment risk of such irAEs.

Autoimmune diabetes induced by PD-1 inhibitor-retrospective analysis and pathogenesis: a case report and literature review

Anti-PD-1 antibody treatment is approved in advanced melanoma and provides median overall survival over 24 months. The main treatment-related side effects are immune-related adverse events, which include rash, pruritus, vitiligo, thyroiditis, diarrhoea, hepatitis and pneumonitis. We report a case of autoimmune diabetes related to nivolumab treatment. A 73-year-old man was treated in second line with nivolumab at 3 mg/kg every two weeks for metastatic melanoma. At 6 weeks of treatment, he displayed diabetic ketoacidosis. Nivolumab was withheld 3.5 weeks and insulin therapy was initiated, enabling a normalization of glycaemia and the disappearance of symptoms. Laboratory investigations demonstrated the presence of islet cell autoantibodies, while C-peptide was undetectable. Retrospective explorations on serum banked at week 0 and 3 months before the start of nivolumab, already showed the presence of autoantibodies, but normal insulin, C-peptide secretion and glycaemia. Partial response was obtained at month 3, and nivolumab was then resumed at the same dose. The clinical context and biological investigations before, at and after nivolumab initiation suggest the autoimmune origin of this diabetes, most likely induced by anti-PD-1 antibody in a predisposed patient. The role of PD-1/PD-L1 binding is well known in the pathogenesis of type 1 diabetes. Therefore, this rare side effect can be expected in a context of anti-PD-1 treatment. Glycaemia should be monitored during PD-1/PD-L1 blockade. The presence of autoantibodies before treatment could identify individuals at risk of developing diabetes, but systematic titration may not be relevant considering the rarity of this side effect.

Endocrine dysfunction following immune checkpoint inhibitor therapy

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICI) represent an important milestone in the modern era of antineoplastic therapy and have ushered optimism amongst oncologists and patients alike. These agents, however, are associated with significant potential toxicities, the importance of which cannot be overstated. The clinical presentation, diagnosis, and management strategies of immune-related endocrinopathies associated with ICI use are described in this case-based review.

RECENT FINDINGS

An increasing number of ICI have shown promise in the management of various malignancies in the recent years. These include cytotoxic T lymphocyte antigen-4 inhibitors, programmed cell death 1 (PD-1) antibodies, and PD-ligand 1 (PD-L1) antibodies. Several endocrinopathies, including hypophysitis, thyroid dysfunction, hyperglycemia, and primary adrenal insufficiency, have been associated with the use of these agents. Toxicities may range from mild transient laboratory abnormalities to potentially life-threatening ones, warranting immediate therapeutic intervention. Combination ICI therapies may be associated with a greater risk of endocrine dysfunction when compared with monotherapy. The clinical presentation and laboratory assessment of these patients often pose a diagnostic challenge as they may be confused by the symptoms related to their underlying malignancy or potential associated acute illnesses.

SUMMARY

ICI use is associated with serious endocrinopathies that may have a nonspecific initial presentation. A constant eye for these symptoms and a systematic approach to diagnosis are essential for prompt initiation of therapy and prevention of significant complications.

Nivolumab-induced autoimmune diabetes mellitus presenting as diabetic ketoacidosis in a patient with metastatic lung cancer

Background

Advances in cancer immunotherapy have generated encouraging results in multiple malignancies refractory to standard chemotherapies. As the use of immune checkpoint inhibitors (ICI) proliferates, the incidence of autoimmune side effects associated with these agents, termed immune related adverse events (irAE), is expected to increase. The frequency of significant irAE in ICI treated patients is about 10–20% and early recognition is critical to prevent serious morbidity and even mortality. New onset autoimmune diabetes mellitus (DM) associated with immune checkpoint inhibitor treatment is extremely rare, occurring in less than 1% of patients. Autoimmune DM often presents as diabetic ketoacidosis, a medical emergency requiring immediate treatment. We describe the first reported case of a patient with lung cancer who developed autoimmune diabetes after nivolumab treatment and was found to have three diabetes related (islet) autoantibodies present before ICI treatment and seroconversion of another after ICI treatment and onset of autoimmune DM.

Case Presentation

A 34 year old African American woman with metastatic non-small cell lung cancer (NSCLC) was treated with nivolumab in the second line setting after disease progression following standard chemoradiation therapy. After receiving two doses of nivolumab, the patient developed abrupt onset of hyperglycemia and diabetic ketoacidosis. Autoimmune diabetes was diagnosed on the basis of undetectable C-peptide levels, seropositivity of three diabetes related (islet) autoantibodies and absolute insulin dependence. The patient eventually required use of continuous subcutaneous insulin infusion (insulin pump) due to erratic glycemic excursions and multiple readmissions for DKA. Human leucocyte antigen (HLA) genoyping revealed none of the high risk haplotypes associated with the development of type 1 diabetes. Interestingly, a frozen blood sample obtained prior to treatment with nivolumab tested positive for three of the four diabetes related (islet) autoantibodies despite no prior history of diabetes and no family history of diabetes. Notably, at the time of manuscript preparation, the patient is without evidence of NSCLC recurrence with no further treatment since the nivolumab therapy.

Conclusion

New onset autoimmune diabetes mellitus associated with nivolumab has been described only in case reports and occurs at rates of < 1% in the large clinical trials which garnered FDA approval in the second line setting for NSCLC. As ICI use continues to expand across a wide variety of malignancies, clinicians must maintain a high index of suspicion for irAE, including autoimmune DM and other endocrinopathies. A multidisciplinary team and thorough education of the patient are recommended to optimize management of new onset adult autoimmune DM. Our patient may have been at greater risk for the development of ICI related autoimmune diabetes due to the presence of three diabetes related autoantibodies prior to therapy; however, about half of the reported cases of autoimmune DM after anti-PD-1 therapy occurred in patients with no detectable diabetes related autoantibodies. Further studies are needed to delineate genetic and immunologic biomarkers that may be useful in identifying patients at risk of developing ICI related autoimmune DM.

An Anti-Programmed Death-1 Antibody (αPD-1) Fusion Protein That Self-Assembles into a Multivalent and Functional αPD-1 Nanoparticle

Cancer immune checkpoint therapy has achieved remarkable clinical successes in various cancers. However, current immune checkpoint inhibitors block the checkpoint of not only the immune cells that are important to cancer therapy but also the immune cells that are irrelevant to the therapy. Such an indiscriminate blockade limits the efficacy and causes the autoimmune toxicity of the therapy. It might be beneficial to use a carrier to target immune checkpoint inhibitors to cancer-reactive immune cells. Here, we explore a method to load the inhibitors into carriers. We used the anti-programmed death-1 antibody (αPD-1) as a model immune checkpoint inhibitor. First, we generated a recombinant single-chain variable fragment (scFv) of αPD-1. Then, we designed and generated a fusion protein consisting of the scFv and an amphiphilic immune-tolerant elastin-like polypeptide (iTEP). Because of the amphiphilic iTEP, the fusion was able to self-assemble into a nanoparticle (NP). The NP was proved to block the PD-1 immune checkpoint in vitro and in vivo. Particularly, the NP exacerbated diabetes development in nonobese diabetic mice as effectively as natural, intact αPD-1. In summary, we successfully expressed αPD-1 as a recombinant protein and linked αPD-1 to a NP, which lays a foundation to develop a delivery system to target αPD-1 to a subpopulation of immune cells.

A case of pembrolizumab-induced type-1 diabetes mellitus and discussion of immune checkpoint inhibitor-induced type 1 diabetes

Immune checkpoint inhibitors such as pembrolizumab, ipilimumab, and nivolumab, now FDA-approved for use in treating several types of cancer, have been associated with immune-related adverse effects. Specifically, the antibodies targeting the programmed-cell death-1 immune checkpoint, pembrolizumab and nivolumab, have been rarely reported to induce the development of type 1 diabetes mellitus. Here we describe a case of a patient who developed antibody-positive type 1 diabetes mellitus following treatment with pembrolizumab in combination with systemic chemotherapy for metastatic adenocarcinoma of the lung. We will also provide a brief literature review of other rarely reported cases of type 1 diabetes presenting after treatment with pembrolizumab and nivolumab, as well as discussion regarding potential mechanisms of this adverse effect and its importance as these drugs continue to become even more widespread.

Genetic risk analysis of a patient with fulminant autoimmune type 1 diabetes mellitus secondary to combination ipilimumab and nivolumab immunotherapy

BACKGROUND

Checkpoint inhibitor immunotherapy is becoming an effective treatment modality for an increasing number of malignancies. As a result, autoinflammatory side-effects are also being observed more commonly in the clinic. We are currently unable to predict which patients will develop more severe toxicities associated with these treatment regimens.

CASE PRESENTATION

We present a patient with stage IV melanoma that developed rapid onset autoimmune type 1 diabetes (T1D) in response to combination ipilimumab and nivolumab immunotherapy. At the time of the patient's presentation with diabetes ketoacidosis, a confirmed anti-GAD antibody seroconversion was noted. Longer-term follow-up of this patient has demonstrated a durable complete response based on PET CT imaging along with a persistently undetectable C-peptide level. Single nucleotide polymorphism gene sequencing and HLA risk allele analysis has revealed the patient to lack any established genetic predisposition to the development of autoimmune T1D.

CONCLUSIONS

While larger studies are necessary to better understand the role of genetic risk factors for the development of autoimmune toxicities in those patients undergoing checkpoint inhibitor immunotherapy, these results suggest that pre-screening patients for known T1D risk alleles may not be indicated. Additional investigation is needed to determine whether an approach such as T cell receptor clonotypic analysis to identify the presence of autoreactive T cell clones may be an effective approach for predicting which patients are at risk for the development of autoinflammatory toxicities while undergoing checkpoint inhibitor immunotherapy.

Glucocorticoids did not reverse type 1 diabetes mellitus secondary to pembrolizumab in a patient with metastatic melanoma

Immune checkpoint inhibitors offer patients with advanced melanoma substantial improvements in survival. Unlike chemotherapy, immune checkpoint inhibitors such as ipilimumab and pembrolizumab cause unique immune-related adverse events (irAEs), including the development of endocrinopathies. We report a case of a man aged 60 years who developed diabetic ketoacidosis (DKA) following the use of pembrolizumab for the treatment of metastatic melanoma. He received four cycles of ipilimumab, before proceeding to pembrolizumab. Five weeks after initiating pembrolizumab, he presented in DKA with a pH of 7.0, bicarbonate of 7 mmol/L, blood glucose of 27 mmol/L and serum ketones of 5.9 mmol/L. Antibodies to glutamic acid decarboxylase (anti-GAD) and Islet antigen 2 (IA-2) were negative and C-peptide was low at 57 pmol/L (300-2350 pmol/L). There was no personal or family history of autoimmune conditions. Standard immunosuppression for irAEs was started using prednisolone in an attempt to salvage β cell function but was unsuccessful. To the best of our knowledge, this is the first reported attempt at reversing pembrolizumab-induced type 1 diabetes using glucocorticoids.

Assessing Immune-Related Adverse Events of Efficacious Combination Immunotherapies in Preclinical Models of Cancer

New combination immunotherapies are displaying both efficacy and immune-related adverse events (irAE) in humans. However, grade 3/4 irAEs occur in a high proportion, which can lead to discontinuation of treatment and can result in fatalities if not promptly treated. Prolonged T regulatory cell (Treg) depletion in tumor-bearing Foxp3-DTR mice using diphtheria toxin (DT) mirrored the spectrum of antitumor responses and severity of irAEs that can occur in ipilimumab/nivolumab-treated patients. In contrast, transient Treg depletion or anti-CTLA-4/PD-1 therapy had equivalent effects in mice, lowering the immune tolerance threshold and allowing irAEs to be more easily induced following treatment with additional immunomodulatory antibodies. Transient Treg depletion of DT in combination with anti-PD-1 or anti-TIM-3 monoclonal antibodies had a high therapeutic window compared with DT plus anti-CD137. In contrast, DT plus anti-CD137-treated mice developed severe irAEs similar to grade 3/4 clinical symptoms. These irAEs appeared because of an infiltration of activated proliferating effector T cells in the tissues producing IFNγ and TNF; however, TNF blockade decreased irAEs severity without impacting on tumor growth. Cancer Res; 76(18); 5288-301. ©2016 AACR.

Hyperglycemia Associated With Targeted Oncologic Treatment: Mechanisms and Management

: Molecularly targeted cancer therapy has rapidly changed the landscape of oncologic care, often improving patients' prognosis without causing as substantial a quality-of-life decrement as cytotoxic chemotherapy does. Nevertheless, targeted agents can cause side effects that may be less familiar to medical oncologists and that require the attention and expertise of subspecialists. In this review, we focus on hyperglycemia, which can occur with use of new anticancer agents that interact with cell proliferation pathways. Key mediators of these pathways include the tyrosine kinase receptors insulin growth factor receptor 1 (IGF-1R) and epidermal growth factor receptor (EGFR), as well as intracellular signaling molecules phosphatidylinositol 3-kinase (PI3K), AKT, and mammalian target of rapamycin (mTOR). We summarize available information on hyperglycemia associated with agents that inhibit these molecules within the larger context of adverse event profiles. The highest incidence of hyperglycemia is observed with inhibition of IGF-1R or mTOR, and although the incidence is lower with PI3K, AKT, and EGFR inhibitors, hyperglycemia is still a common adverse event. Given the interrelationships between the IGF-1R and cell proliferation pathways, it is important for oncologists to understand the etiology of hyperglycemia caused by anticancer agents that target those pathways. We also discuss monitoring and management approaches for treatment-related hyperglycemia for some of these agents, with a focus on our experience during the clinical development of the EGFR inhibitor rociletinib.

IMPLICATIONS FOR PRACTICE

Treatment-related hyperglycemia is associated with several anticancer agents. Many cancer patients may also have preexisting or undiagnosed diabetes or glucose intolerance. Screening can identify patients at risk for hyperglycemia before treatment with these agents. Proper monitoring and management of symptoms, including lifestyle changes and pharmacologic intervention, may allow patients to continue benefiting from use of anticancer agents.

Nivolumab, an Anti-Programmed Cell Death-1 Antibody, Induces Fulminant Type 1 Diabetes

Programmed cell death-1 (PD-1), an immunoreceptor, is located on T cells and pro-B cells and interacts with its ligands to inhibit T cell activation and proliferation, thereby promoting immunological self-tolerance. Nivolumab, an anti-PD1 antibody, blocks PD-1 and can restore anticancer immune responses by abrogating PD-1 pathway-mediated T-cell inhibition. Autoimmune adverse events are expected with PD-1 therapy. Fulminant type 1 diabetes is the subtype of type 1 diabetes. The clinical feature is the extremely rapid progression of hyperglycemia and ketoacidosis. Here we describe a 66-year-old woman with advanced melanoma who was treated with nivolumab. After 4 months and six doses of the medicine, the patient was admitted to the hospital with complaints of nausea and vomiting. The laboratory data showed ketonuria, hyperglycemia (531 mg/dl), high anion gap metabolic acidosis, HbA1c (7.3%), and absence of insulin-secreting capacity. These data are compatible with the criteria of fulminant type 1 diabetes. The patient was diagnosed with diabetic ketoacidosis because of fulminant type 1 diabetes. The findings of this case indicated that nivolumab can cause fulminant type 1 diabetes. Diabetic ketoacidosis due to fulminant type 1 diabetes is potentially fatal condition. Thus, diabetic ketoacidosis due to fulminant type 1 diabetes should be considered in the differential diagnosis when patients treated with nivolumab complain of gastrointestinal symptoms.

Maintenance of peripheral tolerance to islet antigens

Reestablishment of immune tolerance to the insulin-producing beta cells is the desired goal for type 1 diabetes (T1D) treatment and prevention. Immune tolerance to multiple islet antigens is defective in individuals with T1D, but the mechanisms involved are multifaceted and may involve loss of thymic and peripheral tolerance. In this review we discuss our current understanding of the varied mechanisms by which peripheral tolerance to islet antigens is maintained in healthy individuals where genetic protection from T1D is present and how this fails in those with genetic susceptibility to disease. Novel findings in regards to expression of neo-islet antigens, non-classical regulatory cell subsets and the impact of specific genetic variants on tolerance induction are discussed.