Autoimmune Endocrinopathies: An Emerging Complication of Immune Checkpoint Inhibitors

Outcomes and Adverse Events in Patients with Cancer after Diagnosis of Immunotherapy-Associated Diabetes Mellitus: A Retrospective Cohort Study

Immune checkpoint inhibitor (CPI)-induced diabetes mellitus (CPI-DM) is a rare immune-related adverse event (irAE). Patients and providers fear that continuing CPIs puts patients at risk for additional irAEs and thus may discontinue therapy. Currently, there are little data to inform this decision. Therefore, this study aims to elucidate whether discontinuing CPIs after diagnosis of CPI-DM impacts the development of future irAEs and cancer outcomes such as progression and death. Patients who developed CPI-DM during cancer treatment at UCSF from 1 July 2015 to 5 July 2023 were analyzed for cancer outcomes and irAE development. Fisher's exact tests, Student t-tests, Kaplan-Meier methods, and Cox regression were used as appropriate. Of the 43 patients with CPI-DM, 20 (47%) resumed CPIs within 90 days of the irAE, 4 (9%) patients restarted after 90 days, and 19 (44%) patients never restarted. Subsequent irAEs were diagnosed in 9 of 24 (38%) who resumed CPIs and 3 of 19 (16%) who discontinued CPIs (p = 0.17). There was no significant difference in death (p = 0.74) or cancer progression (p = 0.55) between these two groups. While our single-institution study did not show worse cancer outcomes after discontinuing CPIs, many variables can impact outcomes, which our study was not adequately powered to evaluate. A nuanced approach is needed to decide whether to continue CPI treatment after a severe irAE like CPI-DM.

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.

Immune-related adverse events after immune check point inhibitors: Understanding the intersection with autoimmunity

Immune checkpoint inhibitor therapies act through blockade of inhibitory molecules involved in the regulation of T cells, thus releasing tumor specific T cells to destroy their tumor targets. However, immune checkpoint inhibitors (ICI) can also lead to a breach in self-tolerance resulting in immune-related adverse events (irAEs) that include tissue-specific autoimmunity. This review addresses the question of whether the mechanisms that drive ICI-induced irAEs are shared or distinct with those driving spontaneous autoimmunity, focusing on ICI-induced diabetes, ICI-induced arthritis, and ICI-induced thyroiditis due to the wealth of knowledge about the development of autoimmunity in type 1 diabetes, rheumatoid arthritis, and Hashimoto's thyroiditis. It reviews current knowledge about role of genetics and autoantibodies in the development of ICI-induced irAEs and presents new studies utilizing single-cell omics approaches to identify T-cell signatures associated with ICI-induced irAEs. Collectively, these studies indicate that there are similarities and differences between ICI-induced irAEs and autoimmune disease and that studying them in parallel will provide important insight into the mechanisms critical for maintaining immune tolerance.

Real-world adherence to toxicity management guidelines for immune checkpoint inhibitor-induced diabetes mellitus

Objective

Immune checkpoint inhibitors(ICIs) have improved survival and are increasingly used for cancer. However, ICIs use may be limited by immune-related adverse events (irAEs), such as ICI-induced diabetes mellitus(ICI-DM). The objective of the present study was to characterize ICI-DM patients and real-world adherence to guidelines.

Research design and methods

The present study was a retrospective review of electronic records of ICI-DM patients at the First Affiliated Hospital of Nanjing Medical University between July 2018 and October 2022.

Results

34.8% (8/23)patients monitored blood glucose in every treatment cycle. The proportion of patients with severe diabetic ketoacidosis(DKA) was lower in the tight glycemic monitoring group than the non-tight glycemic monitoring group (16.7% vs. 55.6%, p = 0.049). 78.3%(18/23) patients with hyperglycemia visited a non-endocrinologist first, but 95.7% of patients were then referred to an endocrinologist. Twenty patients were tested for distinguishing the etiology of hyperglycemia and 20% patients with positive glutamic acid decarboxylase antibody(GADA), 55% with C-peptide <3.33pmol/L. High screening rates for other ICI-induced endocrinopathies were observed and half of the patients with ICI-DM developed other endocrine gland irAEs, with the most common being thyroiditis. Moreover, five patients developed non-endocrine serious adverse events(SAEs). Twelve (52.2%) patients were withdrawn from ICI due to ICI-DM. The time to progression of tumor in ICI-DM patients in the continue and interruption group was longer than in the withdrawal group (333.5 ± 82.5 days vs. 183.1 ± 62.4 days, p = 0.161). Only 17.4% of ICI-DM patients were completely managed according to guidelines. Thus, the present study proposed a screening, diagnosis, and management algorithm for ICI-DM in real-world practice.

Conclusion

The present study reported the largest number of ICI-DM cases described in a single institute, providing insight into real-world ICI-DM management guideline adherence and highlighting the clinical challenges in ICI-DM management.

Type 1 diabetes

Type 1 diabetes is a chronic disease caused by autoimmune destruction of pancreatic β cells. Individuals with type 1 diabetes are reliant on insulin for survival. Despite enhanced knowledge related to the pathophysiology of the disease, including interactions between genetic, immune, and environmental contributions, and major strides in treatment and management, disease burden remains high. Studies aimed at blocking the immune attack on β cells in people at risk or individuals with very early onset type 1 diabetes show promise in preserving endogenous insulin production. This Seminar will review the field of type 1 diabetes, highlighting recent progress within the past 5 years, challenges to clinical care, and future directions in research, including strategies to prevent, manage, and cure the disease.

Engineered human cytokine/antibody fusion proteins expand regulatory T cells and confer autoimmune disease protection

Low-dose human interleukin-2 (hIL-2) treatment is used clinically to treat autoimmune disorders due to the cytokine's preferential expansion of immunosuppressive regulatory T cells (Tregs). However, off-target immune cell activation and short serum half-life limit the clinical potential of IL-2 treatment. Recent work showed that complexes comprising hIL-2 and the anti-hIL-2 antibody F5111 overcome these limitations by preferentially stimulating Tregs over immune effector cells. Although promising, therapeutic translation of this approach is complicated by the need to optimize dosing ratios and by the instability of the cytokine/antibody complex. We leverage structural insights to engineer a single-chain hIL-2/F5111 antibody fusion protein, termed F5111 immunocytokine (IC), which potently and selectively activates and expands Tregs. F5111 IC confers protection in mouse models of colitis and checkpoint inhibitor-induced diabetes mellitus. These results provide a roadmap for IC design and establish a Treg-biased immunotherapy that could be clinically translated for autoimmune disease treatment.

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.

Optimal Thyroid Hormone Replacement Dose in Immune Checkpoint Inhibitor-Associated Hypothyroidism Is Distinct from Hashimoto's Thyroiditis

Background: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many advanced cancers but are recognized to cause treatment-limiting immune-related adverse events (IrAE). ICI-associated thyroiditis is the most common endocrine IrAE and usually resolves to permanent hypothyroidism. Optimal thyroid hormone replacement in these patients remains unclear. We report the levothyroxine (LT4) dose needed to achieve stable euthyroid state in patients with hypothyroidism from ICI-associated thyroiditis, with comparison to patients with Hashimoto's thyroiditis (HT) and athyreotic state. Methods: We conducted a retrospective study of adults with ICI-associated hypothyroidism treated with LT4 at an academic medical center. Patient data were collected from the electronic medical record. Cases had ICI exposure followed first by hyperthyroidism and then subsequent hypothyroidism. Controls were HT (positive thyroid autoantibodies, requiring LT4) and athyreotic (total thyroidectomy or radioiodine ablation, requiring LT4) patients. Patients with central hypothyroidism, thyroid cancer, pregnancy, gastrointestinal stromal tumors, and use of L-triiodothyronine were excluded. Our primary outcome compared LT4 dose needed to achieve euthyroid state (thyrotropin 0.3-4.7 mIU/L over >6 consecutive weeks) for ICI-associated hypothyroidism, HT, and athyreotic patients, considering the impact of age and possible interfering medications by linear regression modeling. Secondary analysis considered the impact of endocrine specialty care on the time to euthyroid state. Results: One hundred three patients with ICI-associated thyroiditis were identified. Sixty-six of the 103 patients achieved euthyroid state; 2 with intrinsic thyroid gland function recovery and 64 on LT4. The mean LT4 dose achieving stable euthyroid state was 1.45 ± standard deviation (SD) 0.47 mcg/[kg·day] in ICI-associated hypothyroidism, 1.25 ± SD 0.49 mcg/[kg·day] in HT, and 1.54 ± SD 0.38 mcg/[kg·day] in athyreotic patients, using actual body weight. The difference in dose between ICI-associated hypothyroidism and HT was statistically significant (p = 0.0093). Dosing differences were not explained by age or use of interfering medications. Conclusions: ICI-associated thyroiditis represents an increasingly recognized cause of hypothyroidism. Our study demonstrates that patients with ICI-associated hypothyroidism have different thyroid hormone dosing requirements than patients with HT. Based on our findings and prior reports, we recommend that in patients with ICI-associated thyroiditis LT4 therapy be started at an initial weight-based dose of 1.45 mcg/[kg·day] once serum free thyroxine levels fall below the reference range.

Flash Glucose Monitoring and Diabetes Mellitus Induced by Immune Checkpoint Inhibitors: An Approach to Clinical Practice

OBJECTIVES

The aim of this study is to investigate in depth diabetes mellitus associated with immune checkpoint inhibitors (DM-ICIs) by analysing a case series. We also evaluated the clinical impact of flash glucose monitoring (FGM) systems in the management of this entity.

METHODS

We conducted an observational cohort study of DM-ICIs diagnosed in two hospitals in Seville (Spain). Patients with a new diagnosis of diabetes mellitus (DM) or with sudden worsening of preexisting DM after starting treatment with ICIs, with a random 5 hour-postprandial C-peptide value of <0.6 nmol/L and without possibility of subsequent withdrawal of insulin treatment, were included.

RESULTS

A total of 7 cases were identified, mostly males (n = 6; 85.7%), with a mean age of 64.9 years. The mean glycated hemoglobin (HbA1c) upon diagnosis was 8.1%, with diabetic ketoacidosis (DKA) observed in 6 cases (85.7%). Subcutaneous flash glucose monitoring (FGM) systems were used in six cases, with a mean follow-up period of 42.7 weeks. During the first 90 days of use, mean average glucose was 167.5 mg/dL, with a coefficient of variation (CV) of 34.6%. The mean time in the range 70-180 mg/dL (TIR) was 59.7%, with a mean time above range (TAR) 181-250 mg/dL of 27.8% and a mean TAR > 250 mg/dL of 10.2%. The mean time below range (TBR) 54-69 mg/dL was 2%, while the mean TBR < 54 mg/dL was 0.3%. The mean glucose management indicator (GMI) was 7.3%. No significant differences were observed in FGM values for the following 90 days of follow-up. A progressive improvement in all parameters of glycaemic control was observed between the first month of FGM use and the sixth month of FGM use. Of note, there was a decrease in mean CV (40.6% to 34.1%, p = 0.25), mean TAR 181-250 (30.3% to 26%, p = 0.49), mean TAR > 250 mg/dL (16.3% to 7.7%, p = 0.09), mean TBR 54-69 mg/dL (5.2% to 2%, p = 0.16), and mean TBR < 54 mg/dL (1.8% to 0.2%, p = 0.31), along with an increase in mean values of TIR 70-180 mg/dL (46.5% to 60.5%, p = 0.09). The lack of statistical significance in the differences observed in the mean FGM values over the follow-up period may be related to the small sample size.

CONCLUSION

DM-ICI is recognised by a state of sudden-onset insulinopenia, often associated with DKA. The use of FGM systems may be a valid option for the effective management of DM-ICIs and for the prevention of severe hyperglycaemic and hypoglycaemic episodes in this condition.

Thyroid-related adverse events induced by immune checkpoint inhibitors

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

Hypothyroidism as an immune-related adverse event caused by atezolizumab in a patient with muscle spasms: a case report

A 60-year-old man with a history of 4 cycles of atezolizumab treatment for non-small cell lung cancer presented to our hospital with a chief complaint of proximal muscle-dominant spasms. Blood tests showed elevated creatine phosphokinase (CPK) of 8450 U/L and hypothyroidism. There was little improvement even after stopping levetiracetam and pregabalin, and no subspinous physical findings of myositis. After levothyroxine was started for hypothyroidism, his muscle cramps and serum CPK level improved. Hypothyroidism as an immune-related adverse event can cause muscle spasms and is important in the differential diagnosis of muscle spasms in patients treated with immune checkpoint inhibitors.

Patient-Centered Diabetes Care of Cancer Patients

PURPOSE OF REVIEW

There is a bidirectional relationship between cancer and diabetes, with one condition influencing the prognosis of the other. Multiple cancer therapies cause diabetes including well-established medications such as glucocorticoids and novel cancer therapies such as immune checkpoint inhibitors (CPIs) and phosphoinositide 3-kinase (PI3K) inhibitors.

RECENT FINDINGS

The nature and severity of diabetes caused by each therapy differ, with some predominantly mediated by insulin resistance, such as PI3K inhibitors and glucocorticoids, while others by insulin deficiency, such as CPIs. Studies have demonstrated diabetes from CPIs to be more rapidly progressing than conventional type 1 diabetes. There remains a scarcity of published guidance for the screening, diagnosis, and management of hyperglycemia and diabetes from these therapies. The need for such guidance is critical because diabetes management in the cancer patient is complex, individualized, and requires inter-disciplinary care. In the present narrative review, we synthesize and summarize the most relevant literature pertaining to diabetes and hyperglycemia in the setting of these cancer therapies and provide an updated patient-centered framework for their evaluation and management.

Immunotherapy-Mediated Thyroid Dysfunction: Genetic Risk and Impact on Outcomes with PD-1 Blockade in Non-Small Cell Lung Cancer

PURPOSE

Genetic differences in immunity may contribute to toxicity and outcomes with immune checkpoint inhibitor (CPI) therapy, but these relationships are poorly understood. We examined the genetics of thyroid immune-related adverse events (irAE).

EXPERIMENTAL DESIGN

In patients with non-small cell lung cancer (NSCLC) treated with CPIs at Memorial Sloan Kettering (MSK) and Vanderbilt University Medical Center (VUMC), we evaluated thyroid irAEs. We typed germline DNA using genome-wide single-nucleotide polymorphism (SNP) arrays and imputed genotypes. Germline SNP imputation was also performed in an independent Dana-Farber Cancer Institute (DFCI) cohort. We developed and validated polygenic risk scores (PRS) for hypothyroidism in noncancer patients using the UK and VUMC BioVU biobanks. These PRSs were applied to thyroid irAEs and CPI response in patients with NSCLC at MSK, VUMC, and DFCI.

RESULTS

Among 744 patients at MSK and VUMC, thyroid irAEs occurred in 13% and were associated with improved outcomes [progression-free survival adjusted HR (PFS aHR) = 0.68; 95% confidence interval (CI), 0.52-0.88]. The PRS for hypothyroidism developed from UK Biobank predicted hypothyroidism in the BioVU dataset in noncancer patients [OR per standard deviation (SD) = 1.33, 95% CI, 1.29-1.37; AUROC = 0.6]. The same PRS also predicted development of thyroid irAEs in both independent cohorts of patients treated with CPIs (HR per SD = 1.34; 95% CI, 1.08-1.66; AUROC = 0.6). The results were similar in the DFCI cohort. However, PRS for hypothyroidism did not predict CPI benefit.

CONCLUSIONS

Thyroid irAEs were associated with response to anti-PD-1 therapy. Genetic risk for hypothyroidism was associated with risk of developing thyroid irAEs. Additional studies are needed to determine whether other irAEs also have shared genetic risk with known autoimmune disorders and the association with treatment response.

Hypophysitis from immune checkpoint inhibitors: challenges in diagnosis and management

PURPOSE OF REVIEW

This review will summarize the most recent and pertinent evidence regarding immune checkpoint inhibitor (ICI)-induced hypophysitis to describe diagnostic and management algorithm with the help of a case report.

RECENT FINDINGS

Hypophysitis is the most common endocrine adverse event from CTLA-4 inhibitors and much less with PD-1/PD-L1 inhibitors. Its pathophysiology appears to be lymphocytic, predominantly affecting the anterior pituitary. The utility of high-dose glucocorticoids for treatment has been questioned, as they do not influence recovery of hypopituitarism and may reduce survival. A survival benefit with hypophysitis has been suggested.

SUMMARY

The nonspecific nature of symptoms underlies the importance of clinical and hormonal monitoring especially in the first 6 months of CTLA-4 inhibitor cancer therapy. Adrenal insufficiency can be a diagnostic and management challenge, which persists in most cases; hence, a multidisciplinary team of oncologists and endocrinologists is essential for providing high-quality care to these patients. High-dose glucocorticoids should be reserved for mass effect or optic chiasm impingement. The ICI may need to be temporarily withheld but not discontinued. A survival advantage in cancer patients that develop ICI-induced hypophysitis may be a silver lining, especially as ICIs are being investigated for advanced endocrine malignancies.

Type 1 diabetes mellitus: much progress, many opportunities

As part of the centennial celebration of insulin's discovery, this review summarizes the current understanding of the genetics, pathogenesis, treatment, and outcomes in type 1 diabetes (T1D). T1D results from an autoimmune response that leads to destruction of the β cells in the pancreatic islet and requires lifelong insulin therapy. While much has been learned about T1D, it is now clear that there is considerable heterogeneity in T1D with regard to genetics, pathology, response to immune-based therapies, clinical course, and susceptibility to diabetes-related complications. This Review highlights knowledge gaps and opportunities to improve the understanding of T1D pathogenesis and outlines emerging therapies to treat or prevent T1D and reduce the burden of T1D.

Dynamic adoption of anergy by antigen-exhausted CD4+ T cells

Exhausted immune responses to chronic diseases represent a major challenge to global health. We study CD4⁺ T cells in a mouse model with regulatable antigen presentation. When the cells are driven through the effector phase and are then exposed to different levels of persistent antigen, they lose their T helper 1 (Th1) functions, upregulate exhaustion markers, resemble naturally anergic cells, and modulate their MAPK, mTORC1, and Ca²⁺/calcineurin signaling pathways with increasing dose and time. They also become unable to help B cells and, at the highest dose, undergo apoptosis. Transcriptomic analyses show the dynamic adjustment of gene expression and the accumulation of T cell receptor (TCR) signals over a period of weeks. Upon antigen removal, the cells recover their functionality while losing exhaustion and anergy markers. Our data suggest an adjustable response of CD4⁺ T cells to different levels of persisting antigen and contribute to a better understanding of chronic disease.