Case Report: Ipilimumab-Induced Panhypophysitis: An Infrequent Occurrence and Literature Review

Pituitary Complications of Checkpoint Inhibitor Use

Immune checkpoint inhibitors have revolutionized cancer therapy but are associated with a risk of endocrine immune-related adverse events, including pituitary complications. Autoimmune hypophysitis, traditionally a rare diagnosis, has become a more frequently encountered clinical entity with the emergence of antitumor immunotherapy. This mini-review aims to consolidate current knowledge, encompassing the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of pituitary complications of immune checkpoint inhibitor use.

Targeting inflammation as cancer therapy

Inflammation has accompanied human beings since the emergence of wounds and infections. In the past decades, numerous efforts have been undertaken to explore the potential role of inflammation in cancer, from tumor development, invasion, and metastasis to the resistance of tumors to treatment. Inflammation-targeted agents not only demonstrate the potential to suppress cancer development, but also to improve the efficacy of other therapeutic modalities. In this review, we describe the highly dynamic and complex inflammatory tumor microenvironment, with discussion on key inflammation mediators in cancer including inflammatory cells, inflammatory cytokines, and their downstream intracellular pathways. In addition, we especially address the role of inflammation in cancer development and highlight the action mechanisms of inflammation-targeted therapies in antitumor response. Finally, we summarize the results from both preclinical and clinical studies up to date to illustrate the translation potential of inflammation-targeted therapies.

Endocrine side effects of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have increasingly been the mainstay of treatment for numerous malignancies. However, due to their association with autoimmunity, ICIs have resulted in a variety of side effects that involve multiple organs including the endocrine system. In this review article, we describe our current understanding of the autoimmune endocrinopathies as a result of the use of ICIs. We will review the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of the most commonly encountered endocrinopathies, including thyroiditis, hypophysitis, Type 1 diabetes, adrenalitis, and central diabetes insipidus.

Nivolumab plus ipilimumab combination therapy in cancer: Current evidence to date

Immune checkpoint inhibitors (ICIs) have revolutionized cancer immunotherapy, yielding significant antitumor responses across multiple cancer types. Combination ICI therapy with anti-CTLA-4 and anti-PD-1 antibodies outperforms either antibody alone in terms of clinical efficacy. As a consequence, the U.S. Food and Drug Administration (FDA) approved ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) as the first-ever approved therapies for combined ICI in patients with metastatic melanoma. Despite the success of ICIs, treatment with checkpoint inhibitor combinations poses significant clinical challenges, such as increased rates of immune-related adverse events (irAEs) and drug resistance. Thus, identifying optimal prognostic biomarkers could help to monitor the safety and efficacy of ICIs and identify patients who may benefit the most from these treatments. In this review, we will first go over the fundamentals of the CTLA-4 and PD-1 pathways, as well as the mechanisms of ICI resistance. The results of clinical findings that evaluated the combination of ipilimumab and nivolumab are then summarized to support future research in the field of combination therapy. Finally, the irAEs associated with combined ICI therapy, as well as the underlying biomarkers involved in their management, are discussed.

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Diabetes insipidus: A rare endocrine complication of immune check point inhibitors: A case report and literature review

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death protein 1 (PD-1), anti-programmed cell death protein ligand 1 (PD-L1) and anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) monoclonal antibodies, are novel therapeutic agents widely used in numerous malignancies. They are known to cause multiple immune-related endocrine adverse events (irAEs); however, anterior pituitary hypophysitis with secondary hypopituitarism is the most frequently reported irAE, especially in patients receiving anti-CTLA-4 treatment. By contrast, posterior pituitary involvement, such as central diabetes insipidus (CDI), is relatively rare and only few case reports have been published. The present report describes the case of a 53-year-old woman with metastatic melanoma treated with nivolumab an anti-PD-L1 monoclonal antibody. At 6 months after the initiation of nivolumab treatment, the patient was diagnosed with deficiency of the corticotrope and thyreotrope axes and in the following 2 months the patient was diagnosed with progressive development of polyuria-polydipsia syndrome. The diagnosis of partial CDI was retained based on plasma and urinary osmolalities, the water deprivation test and baseline copeptin levels as well as on the absence of the bright spot in the posterior pituitary in magnetic resonance imaging. Systematic research of the literature revealed a total of 13 cases reports (including 14 patients) presenting with CDI treated with monotherapy with CTLA-4 (n=5) or PD-1/PD-L1 Abs (n=6) or combined treatments (n=3). The improved understanding of the mechanisms of ICI action along with their extensive use should contribute to the early recognition of irAE symptoms. We hypothesized that clinicians should be aware of this clinical entity and its symptoms and treat it appropriately.

Immune checkpoint inhibitor-related hypophysitis

Immune checkpoint inhibitors (ICIs) have been recently proposed as a strategy for treating anti-malignant neoplasms. However, this treatment leads to immune-related adverse events (irAEs) such as autoimmune endocrinopathy. Early diagnosis and appropriate treatment of ICI-related hypophysitis are essential as it can manifest as a life-threatening condition due to an adrenal crisis. In this review, we summarize the pathogenesis, risk factors, diagnostic processes, clinical characteristics, and its current management. In particular, we discuss the different aspects of anti-CTLA-4 antibody-related and anti-PD-1/anti-PD-L1 antibody-related hypophysitis. We also propose key points for early detection and diagnosis by identifying the target group that should be monitored more carefully. Specific methods of hormone replacement therapy have also been described. We hope that this review will lead to a better understanding and management of this rare but serious condition during cancer treatment and further elucidate the pathophysiology of pituitary autoimmunity.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Immune Checkpoint Inhibitor-Induced Central Diabetes Insipidus: Looking for the Needle in the Haystack or a Very Rare Side-Effect to Promptly Diagnose?

Immune checkpoint inhibitors have improved the survival in patients affected by an increasing number of malignancies, but they may also trigger various autoimmune side-effects, including endocrinopathies. Very rarely, immune checkpoint inhibitors have been reported to cause central diabetes insipidus. However, with their expanding use, the likelihood that oncologists will face this endocrine adverse event is expected to increase. By reviewing the limited literature on central diabetes insipidus induced by immune checkpoint inhibitors, some inconsistencies emerge in the diagnosis and the management of patients presenting with this toxicity, together with difficulties related to classifying its severity. Until now, specific guidelines on the management of central diabetes insipidus induced by immune checkpoint inhibitors are lacking. In clinical practice, endocrinological consultation may relieve medical oncologists from difficulties in treating this side-effect; oncologists, however, remain responsible for its early diagnose and the management of the causative drugs. To this aim, some practical suggestions are advised for the multidisciplinary management of cancer patients presenting with central diabetes insipidus induced by immune checkpoint inhibitors.

Immune Checkpoint Inhibitors as a Threat to the Hypothalamus-Pituitary Axis: A Completed Puzzle

Immune checkpoint inhibitors (ICI) prolong the survival in an increasing number of patients affected by several malignancies, but at the cost of new toxicities related to their mechanisms of action, autoimmunity. Endocrine toxicity frequently occurs in patients on ICI, but endocrine dysfunctions differ based on the ICI-subclass, as follows: agents targeting the CTLA4-receptor often induce hypophysitis and rarely thyroid dysfunction, which is the opposite for agents targeting the PD-1/PD-L1 axis. Recently, few cases of central diabetes insipidus have been reported as an adverse event induced by both ICI-subclasses, either in the context of anterior hypophysitis or as selective damage to the posterior pituitary or in the context of hypothalamitis. These new occurrences demonstrate, for the first time, that ICI-induced autoimmunity may involve any tract of the hypothalamic-pituitary axis. However, the related pathogenic mechanisms remain to be fully elucidated. Similarly, the data explaining the endocrine system susceptibility to primary and ICI-induced autoimmunity are still scarce. Since ICI clinical indications are expected to expand in the near future, ICI-induced autoimmunity to the hypothalamic-pituitary axis presents as a unique in vivo model that could help to clarify the pathogenic mechanisms underlying both the dysfunction induced by ICI to the hypothalamus-pituitary axis and primary autoimmune diseases affecting the same axis.

Endocrine Toxicities of Antineoplastic Therapy: The Adrenal Topic

Simple Summary

Primary adrenal insufficiency (PAI) induced by anticancer drugs is a rare occurrence. However, with the expanding use of immune checkpoint inhibitors (ICIs), an increasing number of patients affected by ICI-induced PAI are expected. As a result, oncologists should be aware of the risk of PAI in patients on ICIs (and other anticancer agents) and the related clinical presentations to diagnose this condition early, provide the appropriate treatment, and timely involve endocrinologists in the management of those patients. In parallel, patients on these medications, together with their caregivers and relatives, should receive detailed information about PAI risk and be trained to act appropriately at the onset of alarm symptoms. Large collaborative trials are needed to develop appropriate tests to assess the personal risk of drug induced PAI better and improve its early diagnosis in cancer patients and patients affected by other forms of PAI.

Abstract

Immune checkpoint inhibitors (ICIs) have improved survival in patients affected by several solid tumours at the cost of new autoimmune adverse events. Endocrine toxicity is frequently reported in patients treated with these agents, mainly as thyroid dysfunction and hypophysitis. Primary adrenal insufficiency is reported in 1–2% of patients receiving a single ICI, but its rate is approximately 5% in patients treated with a combination of two ICIs. The clinical presentation of adrenal insufficiency may be insidious due to symptoms that are not specific. The same symptoms in cancer patients are frequently multifactorial, rendering the early diagnosis of adrenal insufficiency challenging in this group of patients. As adrenal insufficiency can be fatal if not rapidly diagnosed and treated, oncologists should be aware of its clinical presentations to timely involve endocrinologists to offer patients the appropriate management. In parallel, it is essential to educate patients, their caregivers, and relatives, providing them with detailed information about the risk of adrenal insufficiency and how to manage alarming symptoms at their onset. Finally, large collaborative trials are needed to develop appropriate tests to assess better the personal risk of drug-induced adrenal insufficiency and its early diagnosis and treatment, not only in cancer patients.

Grading Central Diabetes Insipidus Induced by Immune Checkpoint Inhibitors: A Challenging Task

Central diabetes insipidus (CDI) is a rare endocrine disease deriving from an insufficient production or secretion of anti-diuretic hormone. Recently, CDI has been reported as a rare side effect triggered by immune checkpoint inhibitors (ICI) in cancer patients. Despite its current rarity, CDI triggered by ICI is expected to affect an increasing number of patients because of the expanding use of these effective drugs in a growing number of solid and hematologic malignancies. An appropriate assessment of the severity of adverse events induced by anticancer agents is crucial in their management, including dosing adjustment and temporary withdrawal or discontinuation treatment. However, assessment of the severity of CDI induced by ICI may be challenging, as its main signs and symptoms (polyuria, dehydration, weight loss, and hypernatremia) can be incompletely graded. Indeed, the current grading system of toxicity induced by anticancer treatments does not include polyuria. Additionally, dehydration in patients affected by diabetes insipidus, including ICI-induced CDI, is different in certain aspects from that due to other conditions seen in cancer patients, such as vomiting and diarrhea. This prompted us to reflect on the need to grade polyuria, and how to grade it, and to consider a specific grading system for dehydration associated with CDI induced by ICI. Here we propose a new grading system for polyuria and dehydration, as critical symptoms of the CDI syndrome occurring in patients on ICI treatment, to obtain better management of both the adverse event and the triggering drugs.

Stress Axis in the Cancer Patient: Clinical Aspects and Management

Hypothalamus–pituitary–adrenal (HPA) axis alterations are common in cancer patients, mainly due to the different antitumoral therapies, which lead to several acute and late endocrine side effects. This review summarizes the most recent evidence regarding HPA derangement, both in patients with active neoplasms and in cancer survivors, with particular attention to the impact of the different antitumoral treatments, focusing on the major clinical aspects. While acute hormone failure usually results from injury caused directly by tumor burden or surgical interventions, short- and long-term effects are generally due to chemotherapy, radiotherapy and, as more recently shown, to different types of targeted- and immuno-therapy. Adrenal insufficiency (AI) is mostly caused by pituitary or hypothalamic injury rather than a direct damage of the adrenal gland. Moreover, other treatments commonly employed as supportive therapy or in the context of palliative care (i.e., glucocorticoids, opioids) can lead to HPA dysfunction. Epidemiology and pathophysiology of stress axis alterations in cancer patients still require clarification. Since AI may represent a life-threatening condition, monitoring adrenal function in cancer patients is mandatory, especially in subjects who experience fatigue or during stress conditions, in order to promptly start replacement treatment when needed.

Honegger J, M. Weber M, Kroiss M. The Diagnosis and Management of Endocrine Side Effects of Immune Checkpoint Inhibitors

BACKGROUND

The immunologically mediated side effects of immune checkpoint inhibitors (CPI) often involve the endocrine system as well, and they can even be fatal, as in the case of unrecognized hypophysitis. Distinguishing such side effects from tumor-related changes is often difficult, because their clinical features can be nonspecific.

METHODS

This review is based on publications retrieved by a selective search in PubMed, with special attention to international recommendations.

RESULTS

Depending on their target molecules, the CPI now in use differ from one another in the incidence of side effects such as autoimmune thyroid disease (4-16%), hypophysitis (0.1- 18%), adrenalitis (0.7-8%), and autoimmune diabetes mellitus (0.5-2%). The typical clinical warning signs and laboratory constellations of hypophysitis include exhaustion, hyponatremia, and headache. Hypo- and hyperthyroidism and primary adrenocortical insufficiency likewise have nonspecific manifestations. Autoimmune diabetes mellitus often takes a fulminant course. Patients being treated with CPI should be monitored at close intervals, at least as frequently as the administration of the drug, so that endocrine side effects can be recognized in time. In case of doubt, glucocorticoid supplementation should be given whenever hypocortisolism is suspected, even before endocrine evaluation is completed and the results are available. Interrupting or discontinuing CPI treatment is rarely indicated.

CONCLUSION

With the increasing number of patients being treated with CPI, more and more physicians from a wide variety of specialties, not necessarily working in specialized centers, now have to consider immunologically mediated endocrine side effects in the differential diagnosis, and treat them properly when they arise. These things should be done in collaboration with endocrinologists. The ongoing study of such side effects of the CPI now in use, and of those that will be introduced in the future, is important and will lead to improved understanding.

Endocrine Toxicities of Antineoplastic Therapy

In recent years, the prognosis of many solid tumors has improved markedly thanks to new treatment strategies, including tyrosine kinase inhibitors (TKIs) and immunotherapy [...].