Efficacy and safety of osilodrostat in paraneoplastic Cushing's syndrome: a real-world multicenter study in France

Adipose tissue in cortisol excess: What Cushing's syndrome can teach us?

Endogenous Cushing's syndrome (CS) is a rare condition due to prolonged exposure to elevated circulating cortisol levels that features its typical phenotype characterised by moon face, proximal myopathy, easy bruising, hirsutism in females and a centripetal distribution of body fat. Given the direct and indirect effects of hypercortisolism, CS is a severe disease burdened by increased cardio-metabolic morbidity and mortality in which visceral adiposity plays a leading role. Although not commonly found in clinical setting, endogenous CS is definitely underestimated leading to delayed diagnosis with consequent increased rate of complications and reduced likelihood of their reversal after disease control. Most of all, CS is a unique model for systemic impairment induced by exogenous glucocorticoid therapy that is commonly prescribed for a number of chronic conditions in a relevant proportion of the worldwide population. In this review we aim to summarise on one side, the mechanisms behind visceral adiposity and lipid metabolism impairment in CS during active disease and after remission and on the other explore the potential role of cortisol in promoting adipose tissue accumulation.

Two cases of pancreatic neuroendocrine tumors with ectopic ACTH syndrome during their disease course

Pancreatic neuroendocrine tumors (PanNETs) are rare malignant tumors that occur in the pancreas. They are divided into functioning and non-functioning tumors based on the presence or absence of their specific hormonal hyper-expression symptoms. Adrenocorticotropic hormone (ACTH)-producing PanNETs are rare, functional tumors, and their clinical characteristics and outcomes have not been well reported.Here, we report the cases of two patients with PanNETs who presented with ectopic ACTH syndrome (EAS) during the course of their disease. Case 1 involved a non-functioning PanNET at the time of surgery. During treatment for recurrent liver metastases, the patient presented with EAS and tumor-associated hypercalcemia, probably due to ACTH and parathyroid hormone-related peptide (PTHrP) production from the liver tumor. Case 2 was a gastrinoma, and similar to Case 1, this patient presented with EAS during the treatment of recurrent liver metastases.It is not uncommon for patients with PanNETs to have multiple hormones and develop secondary hormone secretion during their disease course, although tumor phenotypes differ between primary and metastatic sites. In patients with functioning PanNETs, symptom control with anti-hormonal therapy is essential, in addition to anti-tumor therapy, especially for EAS, which is an endocrine emergency disease that requires prompt diagnosis and treatment.

A Case of an Ectopic ACTH-Producing Tumor With Adrenal Shrinkage During Osilodrostat Administration

Ectopic adrenocorticotropin (ACTH)-secreting tumors are among the causes of ACTH-dependent Cushing syndrome. When surgical resection of the primary lesion is not feasible, medications such as metyrapone, mitotane, and ketoconazole have been used to control hypercortisolism. This report presents a case treated with the novel drug osilodrostat, wherein the patient's adrenal glands exhibited shrinkage following the initiation of this drug. The case involves a 68-year-old man diagnosed with small cell lung cancer and ectopic ACTH-producing Cushing syndrome. Initially, metyrapone was administered to manage hypercortisolism, but its effect proved insufficient. Subsequently, osilodrostat was initiated while gradually decreasing metyrapone, leading to full suppression of blood cortisol levels. With continued osilodrostat treatment, the adrenal glands reduced in size, suggesting the potential to reduce the osilodrostat dosage.

Prolonged adrenal insufficiency following discontinuation of osilodrostat treatment for intense hypercortisolism

The cases of 3 patients with Cushing's disease who developed long-term adrenal insufficiency after discontinuation of prolonged osilodrostat therapy were recently described for the first time. We report 2 additional cases of persistent prolonged adrenal insufficiency after discontinuation of osilodrostat treatment for intense hypercortisolism due to Cushing's disease and ectopic ACTH syndrome. In addition, we show for that adrenal insufficiency in these patients was associated with low/normal 11-deoxycortisol concentrations despite high plasma ACTH concentrations. These results suggest that CYP11B1 is not the only target of osilodrostat and that, in vivo, osilodrostat has other prolonged and strong inhibitory effect on adrenal steroidogenesis upstream of CYP11B1. Knowledge of this remnant effect is important for the care of patients with Cushing's syndrome treated with osilodrostat. Further studies are needed to clarify the frequency and the mechanisms of this remnant effect.

Cushing's syndrome

Endogenous Cushing's syndrome results from excess glucocorticoid secretion, which leads to a myriad of clinical manifestations, comorbidities, and increased mortality despite treatment. Molecular mechanisms and genetic alterations associated with different causes of Cushing's syndrome have been described in the last decade. Imaging modalities and biochemical testing have evolved; however, both the diagnosis and management of Cushing's syndrome remain challenging. Surgery is the preferred treatment for all causes, but medical therapy has markedly advanced, with new drug options becoming available. Nevertheless, several comorbidities remain even after patient remission, which can affect quality of life. Accurate and timely diagnosis and treatment are essential for mitigating chronic complications of excess glucocorticoids and improving patient quality of life. In this Seminar, we aim to update several important aspects of diagnosis, complications, and treatment of endogenous Cushing's syndrome of all causes.

Pharmacological Treatment of Cushing's Syndrome

The 1st line treatment of Cushing's syndrome is surgery, whatever the aetiology. The role of pharmacological treatment is clear in cases where surgery fails or is impossible, in cases of metastases, or while awaiting the delayed effects of radiotherapy. However, certain situations remain controversial, in particular the possible role of pharmacological treatment as a preparation for surgery. This situation must be divided into 2 parts, severe hypercortisolism with immediate vital risk and non-severe hypercortisolism with diagnostic delay. The initiation and adjustment of treatment doses is also controversial, with the possibility of titration by gradual dose increase based on biological markers, or a more radical "block and replace" approach in which the ultimate goal is to achieve hypocortisolism, which can then be supplemented. Each of these approaches has its advantages and drawbacks and should probably be reserved for different patient profiles depending on the severity of hypercortisolism. In this review, we will focus specifically on these 2 points, namely the potential role of preoperative pharmacological treatment and, more generally, the optimal way to initiate and monitor drug treatment to ensure that eucortisolism or hypocortisolism is achieved. We will define for each part which profiles of patients should be the most adapted to try to give advice on the optimal management of patients with hypercortisolism.

An individualized approach to the management of Cushing disease

Cushing disease caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary corticotroph adenoma leads to hypercortisolaemia with high mortality due to metabolic, cardiovascular, immunological, neurocognitive, haematological and infectious conditions. The disorder is challenging to diagnose because of its common and heterogenous presenting features and the biochemical pitfalls of testing levels of hormones in the hypothalamic-pituitary-adrenal axis. Several late-night salivary cortisol and 24-h urinary free cortisol tests are usually required as well as serum levels of cortisol after a dexamethasone suppression test. MRI might only identify an adenoma in 60-75% of patients and many adenomas are small. Therefore, inferior petrosal sinus sampling remains the gold standard for confirmation of ACTH secretion from a pituitary source. Initial treatment is usually transsphenoidal adenoma resection, but preoperative medical therapy is increasingly being used in some countries and regions. Other management approaches are required if Cushing disease persists or recurs following surgery, including medications to modulate ACTH or block cortisol secretion or actions, pituitary radiation, and/or bilateral adrenalectomy. All patients require lifelong surveillance for persistent comorbidities, clinical and biochemical recurrence, and treatment-related adverse effects (including development of treatment-associated hypopituitarism). In this Review, we discuss challenges in the management of Cushing disease in adults and provide information to guide clinicians when planning an integrated and individualized approach for each patient.

Severe Cushing's syndrome from an ectopic adrenocorticotropic hormone-secreting neuroendocrine tumour treated by osilodrostat

Summary

Severe Cushing's syndrome from an ectopic adrenocorticotropic hormone-producing tumour is rare but often demands rapid diagnostics and treatment of hypercortisolism with its comorbidities. Pharmacotherapy of hypercortisolism by ketoconazole, metyrapone and osilodrostat is currently available. If unsuccessful or insufficient a bilateral adrenalectomy is an option. We present a 28-year-old female with severe Cushing's syndrome caused by a bronchial metastatic neuroendocrine tumour (NET). Hypercortisolism was efficiently treated by osilodrostat with block-replace and then titration regimen. A once-daily dose was finally used with normalised cortisol levels. Androgen levels measured by liquid chromatography-mass spectrometry were slightly elevated during the treatment but without any symptoms. A simple once-daily use of osilodrostat with titration regimen led to normalised cortisol levels in a severe Cushing's syndrome patient with an uncurable bronchial NET. Transient hypocortisolism during treatment appeared but was easily treated by hydrocortisone.

Learning points

Cushing's syndrome from an ectopic adrenocorticotropic hormone-producing tumour is rare. Cortisol upregulation is often severe and rapid, though clinical signs are not always fully pronounced. Rapid treatment is a key for preventing and reducing complications such as fractures, thromboembolism, bleeding, hyperglycaemia, and arterial hypertension. The novel potent steroidogenesis inhibitor osilodrostat can be used as first-line treatment for reducing hypercortisolism.

Successful Management of Cushing Syndrome From Ectopic ACTH Secretion in an Adolescent With Osilodrostat

A previously healthy 11-year-old male was found to have a mass in the pancreatic head after several months of abdominal pain and jaundice. Pathology was consistent with a World Health Organization grade 2 pancreatic neuroendocrine tumor. He developed refractory hypertension and was found to have Cushing syndrome from ectopic ACTH secretion, with oligometastatic liver disease. He underwent surgical resection of the pancreatic tumor and metastases. Postoperatively, his Cushing syndrome resolved, but it reemerged 1 year later in the setting of disease recurrence. He was not a candidate for bilateral adrenalectomy. Ketoconazole therapy was inadequate and he was started on metyrapone, lanreotide, cabergoline, and spironolactone. Although this regimen was well-tolerated, his Cushing syndrome recurred 4 months later as his metastatic disease burden increased. Osilodrostat was begun and the dose was gradually increased in response to his uncontrolled Cushing syndrome. Osilodrostat resulted in rapid improvement and eventual normalization of his urinary free cortisol at a dose of 18 mg twice daily. He had no adverse effects. This rare case highlights the successful off-label use of osilodrostat, a medication intended for refractory Cushing disease in adult patients, in a pediatric patient with Cushing syndrome caused by ectopic ACTH secretion.

Clinical Utility of Osilodrostat in Cushing's Disease: Review of Currently Available Literature

Cushing's disease (CD) is caused by endogenous hypercortisolism as a result of adrenocorticotropin (ACTH) secretion from a pituitary tumor. The condition is associated with multiple comorbidities and increased mortality. First-line therapy for CD is pituitary surgery, performed by an experienced pituitary neurosurgeon. Hypercortisolism may often persist or recur after initial surgery. Patients with persistent or recurrent CD will generally benefit from medical therapy, often administered to patients who underwent radiation therapy to the sella and are awaiting its salutary effects. There are three groups of medications directed against CD, including pituitary-targeted medications that inhibit ACTH secretion from tumorous corticotroph cells, adrenally-directed medications that inhibit adrenal steroidogenesis and a glucocorticoid receptor (GR) antagonist. The focus of this review is osilodrostat, a steroidogenesis inhibitor. Osilodrostat (LCI699) was initially developed to lower serum aldosterone levels and control hypertension. However, it was soon realized that osilodrostat also inhibits 11-beta hydroxylase (CYP11B1), leading to a reduction in serum cortisol levels. The focus of drug development then shifted from treatment of hypertension to treatment of hypercortisolism in CD. In a series of studies (LINC 1 through 4), osilodrostat was shown to be effective in normalizing 24-h urinary free cortisol (UFC) in the majority of treated patients and was approved for patients with CD who have failed surgery or are not surgical candidates. Further study is needed to examine the role of combination therapy as well as long-term outcomes of treated patients. Osilodrostat was shown to have an overall good safety profile. Most common adverse effects include nausea, headache, fatigue, arthralgias, dizziness, prolonged QTc interval, hypokalemia. In females, the drug can cause hirsutism and acne. Osilodrostat is administered twice daily, making it a good choice for patients with difficulty adhering to more complex regimens. Osilodrostat has an important, albeit adjunctive, role in the management of patients with CD.