Metyrapone treatment in Cushing's syndrome: a real-life study

Adrenal Cushing Syndrome: Diagnosis and Management in a 10-Year-Old Boy with Carney Complex

INTRODUCTION

Adrenocorticotropic hormone (ACTH)-independent Cushing syndrome (CS) is very rare condition in children. Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of CS, which in most cases occurs in the context of Carney complex (CNC). CNC is a rare autosomal-dominantly inherited genetic syndrome, usually due to pathogenic variants of the PRKAR1A (regulatory subunit R1A of the protein kinase A) gene located at 17q22-24. The clinical picture is characterized by spotty skin pigmentation, cardiac, cutaneous, and mammary myxomas, melanocytic schwannomas, endocrinopathies, and tumours of the endocrine glands (mostly adrenal, pituitary, and thyroid).

CASE PRESENTATION

A 10-year-old boy first came to our outpatient clinic due to severe obesity. During the first 3 months of follow-up, the height growth rate was normal, but the response to dietary-behavioural indications was poor in terms of weight loss. Later, 10 months after the last evaluation, there was evidence of significant worsening of obesity, growth failure (growth velocity 0.7 cm/year), arterial hypertension, and the occurrence of violaceous striae at the trunk and root of the limbs. Endocrinological causes of obesity associated with growth failure were investigated. The circadian rhythm of cortisol, ACTH, and cortisoluria were suggestive of ACTH-independent hypercortisolaemia. Iatrogenic causes were ruled out. Adrenal ultrasound and computer tomography scan were performed, which initially indicated the presence of a nodule or hyperplasia of the medial arm of the left adrenal gland. Conversely, magnetic resonance imaging showed a significant increase in the global dimensions of the adrenals with a bilateral micronodular appearance. In light of the association between ACTH-independent hypercortisolism and bilateral micronodular adrenal hyperplasia, a genetic investigation was performed, which found a pathogenic variant of the PRKAR1A gene. The patient was begun on treatment with metyrapone which was well tolerated over a 2-year period. The clinical picture has slightly improved, cortisoluria returned and remains within normal limits, but ACTH suppression persists.

CONCLUSION

This is the first report on the clinical and biochemical effects of 2-year medical treatment with metyrapone of PPNAD-related hypercortisolaemia in a paediatric patient with CNC. Currently, there are no established protocols for the management of hypercortisolism in PPNAD and data are scarce, especially in the paediatric field. Medical therapies may play a role in reducing the need, at least initially, for patients to undergo bilateral adrenalectomy. However, further studies on larger case series are needed to clarify this aspect. In cases of CS due to PPNAD in which medical therapy was the initial approach, in the absence of clear clinical, auxological, and biochemical improvements, metyrapone may have to be discontinued in favour of another approach, including surgery.

Medical Therapy of Endogenous Cushing's Syndrome with Steroidogenesis Inhibitors: Treatment Rationale, Available Drugs, and Therapeutic Effects

Endogenous Cushing's syndrome (CS) is a rare disease characterized by a glucocorticoid excess. If inadequately treated, hypercortisolism can lead to increased morbidity and mortality. Surgical removal of the underlying tumor is the first-line treatment but is sometimes not feasible or even contraindicated. Additionally, in cases with severe CS, rapid control of hypercortisolism may be required. In these scenarios, steroidogenesis inhibitors represent a therapeutic alternative to surgery. Over the last years, the knowledge of the broad therapeutic effects of steroidogenesis inhibitors per se and the number of available drugs have increased. However, large comparative studies are still lacking. Accordingly, the decision on which drug to be used in a certain patient or clinical setting may be difficult. This review aims to summarize the main characteristics of steroidogenesis inhibitors.

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.

A clinical perspective on ectopic Cushing's syndrome

Cushing's syndrome (CS) refers to the clinical features of prolonged pathological glucocorticoid excess. About 10-20% of individuals with CS have ectopic CS (ECS), that is, an adrenocorticotropin (ACTH)-producing tumour outside the pituitary gland. ACTH-secreting neuroendocrine neoplasia (NENs) can arise from many organs, although bronchial NEN, small cell lung cancer (SCLC), pancreatic NEN, thymic NEN, medullary thyroid cancer (MTC), and pheochromocytoma are the most common. Patients with ECS frequently present with severe hypercortisolism. The risk of life-threatening complications is high in severe cases, unless the hypercortisolism is effectively treated. A good outcome in ECS requires a methodical approach, incorporating prompt diagnosis, tumour localization, control of cortisol excess, and resection of the primary tumour when possible.

Current and Emerging Pharmacological Therapies for Cushing's Disease

Cushing's Disease (CD), hypercortisolism due to pituitary ACTH secreting neuroendocrine neoplasm, is associated with increased morbidity and, if untreated, mortality in about half of the affected individuals. Consequently, the timely initiation of effective treatment is mandatory. Neurosurgery is the first line and the only potentially curative treatment; however, 30% of patients will have persistent disease post-surgery. Furthermore, a small percentage of those initially controlled will develop hypercortisolism during long-term follow- up. Therefore, patients with persistent or recurrent disease, as well as those considered non-eligible for surgery, will need a second-line therapeutic approach, i.e., pharmacotherapy. Radiation therapy is reserved as a third-line therapeutic option due to its slower onset of action and its unfavorable profile regarding complications. During the past few years, the understanding of molecular mechanisms implicated in the physiology of the hypothalamus-pituitary-adrenal axis has evolved, and new therapeutic targets for CD have emerged. In the present review, currently available treatments, compounds currently tested in ongoing clinical trials, and interesting, potentially new targets emerging from unraveling molecular mechanisms involved in the pathophysiology of Cushing's disease are discussed.

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.

Evidence of Persistent Mild Hypercortisolism in Patients Medically Treated for Cushing Disease: the Haircush Study

CONTEXT

Cortisol-lowering drugs may not restore a normal cortisol secretion in Cushing disease (CD).

OBJECTIVE

This work aimed to assess the long-term cortisol exposure in medically treated CD patients using hair-cortisol (HF) and hair-cortisone (HE) measurement.

METHODS

This multicenter prospective study included 3 groups of female patients: CushMed = 16 treated with a stable cortisol-lowering drug dosage and normal urinary free cortisol (UFC); CushSurg = 13 cured by pituitary surgery; CushBla = 15 receiving stable recommended doses of hydrocortisone following bilateral adrenalectomy. Patients were evaluated for 3 months with their usual treatments. Two late-night saliva and 24-hour urine samples were collected monthly in CushMed, and at study end in CushSurg and CushBla patients. A 3-cm hair sample was collected at study end from all patients. Main outcome measures included clinical score and centralized measurement of UFC, late-night salivary cortisol (LNSF), late-night salivary cortisone (LNSE), HE, HF.

RESULTS

Despite having almost all UFCs normalized, CushMed patients exhibited increased HE as compared to CushSurg controls (P = .003). CushMed patients also had increased clinical score (P = .001), UFC (P = .03), LNSF, LNSE (P = .0001), and variability in the latter parameters (P = .004). CushBla patients had increased HF and HE, contrasting with LNSEs similar to CushSurg patients. Six of 15 CushMed patients exhibited increased HE concentrations and had increased antihypertensive drug dosage compared to CushMed patients with normal HE (P = .05).

CONCLUSION

Despite normalized UFCs, a subset of medically treated CD patients displays an altered circadian rhythm of serum cortisol. A single HE measurement identifies chronic mild persistent hypercortisolism and could replace multiple saliva analyzes to monitor medical treatments in CD patients once UFC is normalized.

Metyrapone Treatment Protects Low-Density Lipoprotein Receptor Knockout Mice against Hypercorticosteronemia Development without Changing Atherosclerosis Susceptibility

The steroid 11beta-hydroxylase inhibitor metyrapone is able to effectively reverse the hypercortisolemia detected in human Cushing's Syndrome patients. In this current preclinical study, we investigated whether metyrapone monotherapy can also reverse the hypercortisolemia-associated increase in atherosclerotic cardiovascular disease risk. In this instance, female low-density lipoprotein receptor knockout mice fed a cholic acid-containing high cholesterol/high fat diet to induce the development of hypercorticosteronemia and atherosclerotic lesions were treated twice daily with 100 mg/kg metyrapone for 4 weeks. Metyrapone effectively protected against hypercorticosteronemia development with endpoint plasma corticosterone levels remaining 43% lower than in controls (p < 0.01). Gene expression analysis in livers and adrenals validated that glucocorticoid receptor signaling was also reduced. Importantly, metyrapone treatment did not impact plasma cholesterol levels or alter atherosclerotic plaque areas or lesional collagen contents. However, metyrapone induced significant systemic lymphocytopenia as evident from marked decreases in splenic white pulp contents and thymus weights (-48% and -41%, respectively; p < 0.001). In conclusion, we have shown that treatment with metyrapone diminishes hypercorticosteronemia without affecting atherosclerosis susceptibility in cholic acid-containing high cholesterol/high fat diet-fed low-density lipoprotein receptor knockout mice. These preclinical findings highlight that restoring plasma glucocorticoid levels to normal is not necessarily sufficient to overcome the cardiovascular co-morbidities associated with human Cushing's disease.

Long-term efficacy and safety of osilodrostat in patients with Cushing's disease: results from the LINC 4 study extension

Objective

To evaluate the long-term efficacy and safety of osilodrostat in patients with Cushing's disease.

Methods

The multicenter, 48-week, Phase III LINC 4 clinical trial had an optional extension period that was initially intended to continue to week 96. Patients could continue in the extension until a managed-access program or alternative treatment became available locally, or until a protocol amendment was approved at their site that specified that patients should come for an end-of-treatment visit within 4 weeks or by week 96, whichever occurred first. Study outcomes assessed in the extension included: mean urinary free cortisol (mUFC) response rates; changes in mUFC, serum cortisol and late-night salivary cortisol (LNSC); changes in cardiovascular and metabolic-related parameters; blood pressure, waist circumference and weight; changes in physical manifestations of Cushing's disease; changes in patient-reported outcomes for health-related quality of life; changes in tumor volume; and adverse events. Results were analyzed descriptively; no formal statistical testing was performed.

Results

Of 60 patients who entered, 53 completed the extension, with 29 patients receiving osilodrostat for more than 96 weeks (median osilodrostat duration: 87.1 weeks). The proportion of patients with normalized mUFC observed in the core period was maintained throughout the extension. At their end-of-trial visit, 72.4% of patients had achieved normal mUFC. Substantial reductions in serum cortisol and LNSC were also observed. Improvements in most cardiovascular and metabolic-related parameters, as well as physical manifestations of Cushing's disease, observed in the core period were maintained or continued to improve in the extension. Osilodrostat was generally well tolerated; the safety profile was consistent with previous reports.

Conclusion

Osilodrostat provided long-term control of cortisol secretion that was associated with sustained improvements in clinical signs and physical manifestations of hypercortisolism. Osilodrostat is an effective long-term treatment for patients with Cushing's disease.

Clinical trial registration

ClinicalTrials.gov, identifier NCT02180217.

Unmet needs on the current medical management of Cushing's syndrome: results from a Delphi panel of Italian endocrinologists

BACKGROUND

Cushing's syndrome (CS) is a rare clinical condition caused by excessive cortisol secretion from adrenal glands. CS is associated with increased mortality and morbidity; therefore, a prompt diagnosis and an effective therapeutic approach are strongly necessary to improve the patient's clinical management. The first-line treatment for CS is surgery, while medical treatment has historically played a minor role. However, thanks to the availability of novel compounds, the possibility of improving hypercortisolism control using different drug combinations emerged.

PURPOSE

No absolute recommendations are available to guide the therapeutic choice for patients with CS and, consequently, the awareness of unmet needs in CS management is growing. Although new data from clinical trials are needed to better define the most appropriate management of CS, an expert consensus approach can help define unmet needs and optimize the current CS management and treatment.

METHODS

Twenty-seven endocrinologists from 12 Italian regions, working among the main Italian referral centers for hospital endocrinology where they take care of CS patients, were involved in a consensus process and used the Delphi method to reach an agreement on 24 statements about managing CS patients.

RESULTS

In total, 18 statements reached a consensus. Some relevant unmet needs in the management of CS were reported, mainly related to the lack of a pharmacological treatment successful for the majority of patients.

CONCLUSION

While acknowledging the difficulty in achieving complete disease control, a significant change in CS management requires the availability of medical treatment with improved efficacy and safety over available therapeutic options at the time of the current study.

An evaluation of pharmacological options for Cushing's disease: what are the state-of-the-art options?

INTRODUCTION

Untreated Cushing's syndrome (CS) is associated with significant morbidity and mortality. Cortisol normalization is a key goal to treatment. Pituitary surgery remains the first-line approach for Cushing's disease, but sometimes it is impracticable, unsuccessful, or complicated by recurrence. Medical therapy has been historically considered a palliative. However, in the latest years, interest on this topic has grown due to both the availability of new drugs and the reevaluation of the old, commonly used drugs in clinical practice.

AREAS COVERED

In this article, we will discuss the current options and future directions of medical therapy for CS, aiming at fitting best patients' features. An extensive literature search regarding already approved and investigational principles was conducted (PubMed, ClinicalTrials.gov. Available drugs include inhibitors of ACTH secretion, steroidogenesis inhibitors, and glucocorticoid receptor antagonists; drugs acting at different levels can be also combined in uncontrolled patients.

EXPERT OPINION

Since there is still no standardized pharmacological approach and the superiority of one drug over another has not been established yet in the absence of comparative studies, each time clinicians' choices should be patient-tailored. Age, gender, tumor features, severity of hypercortisolism, comorbidities/complications, rapidity of action, side effects, drug-drug interactions, contraindications, availability, patients' preferences, and costs should be all considered.

Medical treatment of Cushing's disease with concurrent diabetes mellitus

Cushing's disease (CD) is a severe endocrine disorder characterized by chronic hypercortisolaemia secondary to an overproduction of adrenocorticotropic hormone (ACTH) by a pituitary adenoma. Cortisol excess impairs normal glucose homeostasis through many pathophysiological mechanisms. The varying degrees of glucose intolerance, including impaired fasting glucose, impaired glucose tolerance, and Diabetes Mellitus (DM) are commonly observed in patients with CD and contribute to significant morbidity and mortality. Although definitive surgical treatment of ACTH-secreting tumors remains the most effective therapy to control both cortisol levels and glucose metabolism, nearly one-third of patients present with persistent or recurrent disease and require additional treatments. In recent years, several medical therapies demonstrated prominent clinical efficacy in the management of patients with CD for whom surgery was non-curative or for those who are ineligible to undergo surgical treatment. Cortisol-lowering medications may have different effects on glucose metabolism, partially independent of their role in normalizing hypercortisolaemia. The expanding therapeutic landscape offers new opportunities for the tailored therapy of patients with CD who present with glucose intolerance or DM, however, additional clinical studies are needed to determine the optimal management strategies. In this article, we discuss the pathophysiology of impaired glucose metabolism caused by cortisol excess and review the clinical efficacy of medical therapies of CD, with particular emphasis on their effects on glucose homeostasis.

How best to monitor the specific side effects of medical treatments of Cushing's disease

The first-line treatment of Cushing's disease is transsphenoidal surgery. Medical treatment of Cushing's disease can be considered in several situations: as a presurgical treatment in patients with severe comorbidities, when surgery fails, or while waiting for the maximal efficacy of radiation techniques. Several modalities of medical treatment are possible, from adrenal-targeting drugs (steroidogenesis inhibitors) to pituitary-targeting drugs (somatostatin receptor ligand pasireotide or the dopamine agonist cabergoline), or even drugs that antagonize the glucocorticoid receptor (mifepristone). Given the morbidities associated with hypercortisolism, and the fact that medical treatment can be delivered on a long-term basis, it is important to obtain eucortisolism and to monitor the drug effectively. The efficacy of these drugs will not be detailed in this review, nor their roles in the therapeutic algorithm of Cushing's disease. This review will rather focus specifically on adverse events associated with these drugs (ketoconazole, levoketoconazole, metyrapone, osilodrostat, pasireotide, cabergoline and mifepristone), and the way in which to monitor and treat them, based on retrospective studies and the most recently published prospective studies.

Advanced Adrenocortical Carcinoma: From Symptoms Control to Palliative Care

The prognosis of patients with advanced adrenocortical carcinoma (ACC) is often poor: in the case of metastatic disease, five-year survival is reduced. Advanced disease is not a non-curable disease and, in referral centers, the multidisciplinary approach is the standard of care: if a shared decision regarding several treatments is available, including the correct timing for the performance of each one, overall survival is increased. However, many patients with advanced ACC experience severe psychological and physical symptoms secondary to the disease and the cancer treatments. These symptoms, combined with existential issues, debase the quality of the remaining life. Recent strong evidence from cancer research supports the early integration of palliative care principles and skills into the advanced cancer patient's trajectory, even when asymptomatic. A patient with ACC risks quickly suffering from symptoms/effects alongside the disease; therefore, early palliative care, in some cases concurrent with oncological treatment (simultaneous care), is suggested. The aims of this paper are to review current, advanced ACC approaches, highlight appropriate forms of ACC symptom management and suggest when and how palliative care can be incorporated into the ACC standard of care.

Cushing's disease: adrenal steroidogenesis inhibitors

Cushing's disease (CD), caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary tumor, is the most common form of Cushing's syndrome (CS), accounting for approximately 70% of cases. CD requires a prompt diagnosis, an adequate treatment selection, and long-term management to limit hypercortisolism duration and long-term complications and improve patient outcomes. Pituitary surgery is the first-line option, which is non-curative in one third of patients, therefore requiring additional treatments. Medical therapy has recently acquired an emerging role, with the availability of several drugs with different therapeutic targets, efficacy and safety profiles. The current review focuses on efficacy and safety of steroidogenesis inhibitors, and particularly the historical drugs, ketoconazole and metyrapone, and the novel drugs levoketoconazole and osilodrostat, which seem to offer a rapid, sustained, and effective disease control. Ketoconazole should be preferred in females and in patients without severe liver disease; levoketoconazole may offer an alternative to classical ketoconazole, appearing characterized by a higher potency and potential lower hepatotoxicity compared to ketoconazole. Metyrapone should be preferred in males and in patients without severe or uncontrolled hypokalemia. Both ketoconazole and metyrapone may be preferred for short-term more than for long-term treatment. Osilodrostat may represent the best choice for long-term treatment, in patients with poor compliance to the multiple daily administration schedule, and in patients without severe or uncontrolled hypokalemia. Steroidogenesis inhibitors may be used alone or in combination, and associated with pituitary directed drugs, to improve the efficacy of the single drugs, allowing a potential use of lower doses for each drug, and hypothetically reducing the rate of adverse events associated with the single drugs. Clinicians may tailor medical therapy on the specific clinical scenario, considering disease history together with patients' characteristics and hypercortisolism's degree, addressing the needs of each patient in order to improve the therapeutic outcome and to reduce the burden of illness, particularly in patients with persistent or recurrent CD.

Long-term outcomes of osilodrostat in Cushing's disease: LINC 3 study extension

OBJECTIVE

To investigate the long-term efficacy and tolerability of osilodrostat, a potent oral 11β-hydroxylase inhibitor, for treating Cushing's disease (CD).

DESIGN/METHODS

A total of 137 adults with CD and mean 24-h urinary free cortisol (mUFC) > 1.5 × upper limit of normal (ULN) received osilodrostat (starting dose 2 mg bid; maximum 30 mg bid) during the prospective, Phase III, 48-week LINC 3 (NCT02180217) core study. Patients benefiting from osilodrostat at week 48 could enter the optional extension (ending when all patients had received ≥ 72 weeks of treatment or discontinued). Efficacy and safety were assessed for all enrolled patients from the core study baseline.

RESULTS

Median osilodrostat exposure from the core study baseline to study end was 130 weeks (range 1-245) and median average dose was 7.4 mg/day (range 0.8-46.6). The reduction in mean mUFC achieved during the core was maintained during the extension and remained ≤ ULN. Of 106 patients, 86 (81%) patients who entered the extension had mUFC ≤ ULN at week 72. Improvements in cardiovascular/metabolic-related parameters, physical manifestations of hypercortisolism (fat pads, central obesity, rubor, striae, and hirsutism in females), and quality of life in the core study were also maintained or improved further during the extension. No new safety signals were reported; 15/137 (10.9%) and 12/106 (11.3%) patients discontinued for adverse events during the core and extension, respectively. Mean testosterone in females decreased towards baseline levels during the extension.

CONCLUSIONS

Data from this large, multicentre trial show that long-term treatment with osilodrostat sustains cortisol normalisation alongside clinical benefits in most patients with CD and is well tolerated.

Long-term morbidity and mortality in patients with Cushing's syndrome

Increased multisystem morbidity and mortality in patients with Cushing's syndrome comprise clinical problems and challenges, both at the time of diagnosis and in remission. Relevant comorbidities and clinical problems include hypertension, diabetes, overweight, myopathy and a high risk for acute complications such as infections and venous thrombembolism. Although there are therapy recommendations for most of these comorbidities, there is a lack of large, prospective studies to confirm and optimise them. Mortality is especially high during active disease and within the first year after diagnosis, as a result of cardiovascular events, infections and suicide. All in all, interdisciplinary therapy management is important for reducing morbidity and mortality over the long-term.

Differences in the spectrum of steroidogenic enzyme inhibition between Osilodrostat and Metyrapone in ACTH-dependent Cushing syndrome patients

INTRODUCTION

Osilodrostat is a new 11β-hydroxylase inhibitor with a mode of action analogous to Metyrapone. The objective of this study was to compare steroidogenic profiles in patients treated with either Osilodrostat or Metyrapone for adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome (CS).

METHODS

Patients followed up at Cochin hospital Endocrinology department between March 2019 and December 2021 for an ACTH-dependent CS, controlled by either Osilodrostat or Metyrapone, were included. A serum profile of five steroids (cortisol, 11-deoxycortisol, 17-hydroxyprogesterone, androstenedione and testosterone) was determined using UPLC- tandem mass spectrometry (UPLC-MS/MS).

RESULTS

Nineteen patients treated with Osilodrostat, eight patients treated with Metyrapone and six patients treated with consecutive Metyrapone then Osilodrostat were included. Hypocortisolism (basal cortisol <100 nmol/L) was found in 48% of patients treated with Osilodrostat and 7% of patients treated with Metyrapone. 11-deoxycortisol and androstenedione levels were higher in patients treated with Metyrapone (80.9 (2.2-688.4) and 14.9 (2.5-54.3) nmol/L, respectively) than in patients treated with Osilodrostat (10.3 (0.5-71.9) and 4.0 (0.3-13.3) nmol/L) (P = 0.0009 and P = 0.0005). Testosterone level in women was also higher in Metyrapone group (3.3 (0.93-4.82) nmol/L vs 1.31(0.13-5.09) nmol/L, P = 0.0146). CYP11B1 activity (11-deoxycortisol/cortisol) was not significantly different between the two groups. CYP21A2 activity (17OHprogesterone/11-deoxycortisol) and CYP17A1 activity (17OHprogesterone/androstenedione) were significantly decreased in Osilodrostat group (P < 0.0001).

CONCLUSION

In patients with ACTH-dependent CS, the use of CYP11B1 inhibitors in routine care suggests that Osilodrostat has a less specific effect on the inhibition of steroidogenic enzymes than Metyrapone. This might explain a smaller increase in 11-deoxycortisol and androgen levels in patients treated with Osilodrostat.

Unmet needs in Cushing's syndrome: the patients' perspective

BACKGROUND

Cushing's syndrome (CS) is a rare condition of chronically elevated cortisol levels resulting in diverse comorbidities, many of which endure beyond successful treatment affecting the quality of life. Few data are available concerning patients' experiences of diagnosis, care and persistent comorbidities.

OBJECTIVE

To assess CS patients' perspectives on the diagnostic and care journey to identify unmet therapeutic needs.

METHODS

A 12-item questionnaire was circulated in 2019 by the World Association for Pituitary Organisations. A parallel, 13-item questionnaire assessing physician perceptions on CS patient experiences was performed.

RESULTS

Three hundred twenty CS patients from 30 countries completed the questionnaire; 54% were aged 35-54 and 88% were female; 41% were in disease remission. The most burdensome symptom was obesity/weight gain (75%). For 49% of patients, time to diagnosis was over 2 years. Following treatment, 88.4% of patients reported ongoing symptoms including, fatigue (66.3%), muscle weakness (48.8%) and obesity/weight gain (41.9%). Comparisons with delay in diagnosis were significant for weight gain (P = 0.008) and decreased libido (P = 0.03). Forty physicians completed the parallel questionnaire which showed that generally, physicians poorly estimated the prevalence of comorbidities, particularly initial and persistent cognitive impairment. Only a minority of persistent comorbidities (occurrence in 1.3-66.3%; specialist treatment in 1.3-29.4%) were managed by specialists other than endocrinologists. 63% of patients were satisfied with treatment.

CONCLUSION

This study confirms the delay in diagnosing CS. The high prevalence of persistent comorbidities following remission and differences in perceptions of health between patients and physicians highlight a probable deficiency in effective multidisciplinary management for CS comorbidities.

Randomized Trial of Osilodrostat for the Treatment of Cushing Disease

CONTEXT

Cushing disease, a chronic hypercortisolism disorder, is associated with considerable morbidity and mortality. Normalizing cortisol production is the primary treatment goal.

OBJECTIVE

We aimed to evaluate the safety and efficacy of osilodrostat, a potent, orally available 11βhydroxylase inhibitor, compared with placebo in patients with Cushing disease.

METHODS

LINC 4 was a phase III, multicenter trial comprising an initial 12-week, randomized, double-blind, placebo-controlled (osilodrostat:placebo, 2:1) period followed by a 36-week, open-label treatment period (NCT02697734). Adult patients (aged 18-75 years) with confirmed Cushing disease and mean urinary free cortisol (mUFC) excretion ≥ 1.3 times the upper limit of normal (ULN) were eligible. The primary endpoint was the proportion of randomized patients with mUFC ≤ ULN at week 12. The key secondary endpoint was the proportion achieving mUFC ≤ ULN at week 36 (after 24 weeks' open-label osilodrostat).

RESULTS

Seventy-three patients (median age, 39 years [range, 19-67]; mean/median mUFC, 3.1 × ULN/2.5 × ULN) received randomized treatment with osilodrostat (n = 48) or placebo (n = 25). At week 12, significantly more osilodrostat (77%) than placebo (8%) patients achieved mUFC ≤ ULN (odds ratio 43.4; 95% CI 7.1, 343.2; P < 0.0001). Response was maintained at week 36, when 81% (95% CI 69.9, 89.1) of all patients achieved mUFC ≤ ULN. The most common adverse events during the placebo-controlled period (osilodrostat vs placebo) were decreased appetite (37.5% vs 16.0%), arthralgia (35.4% vs 8.0%), and nausea (31.3% vs 12.0%).

CONCLUSION

Osilodrostat rapidly normalized mUFC excretion in most patients with Cushing disease and maintained this effect throughout the study. The safety profile was favorable.

The Role of Glucocorticoid Receptor in the Pathophysiology of Pituitary Corticotroph Adenomas

Adrenocorticotropic Hormone (ACTH)-secreting pituitary adenomas are rare tumors characterized by autonomous ACTH secretion with a consequent increase in circulating cortisol levels. The resulting clinical picture is called Cushing’s disease (CD), a severe condition burdened with high morbidity and mortality. Apart from increased cortisol levels, CD patients exhibit a partial resistance to the negative glucocorticoid (GC) feedback, which is of paramount clinical utility, as the lack of suppression after dexamethasone administration is one of the mainstays for the differential diagnosis of CD. Since the glucocorticoid receptor (GR) is the main regulator of negative feedback of the hypothalamic–pituitary–adrenal axis in normal conditions, its implication in the pathophysiology of ACTH-secreting pituitary tumors is highly plausible. In this paper, we review GR function and structure and the mechanisms of GC resistance in ACTH-secreting pituitary tumors and assess the effects of the available medical therapies targeting GR on tumor growth.

Glucocorticoid Withdrawal Syndrome following treatment of endogenous Cushing Syndrome

PURPOSE

Literature regarding endogenous Cushing syndrome (CS) largely focuses on the challenges of diagnosis, subtyping, and treatment. The enigmatic phenomenon of glucocorticoid withdrawal syndrome (GWS), due to rapid reduction in cortisol exposure following treatment of CS, is less commonly discussed but also difficult to manage. We highlight the clinical approach to navigating patients from GWS and adrenal insufficiency to full hypothalamic-pituitary-adrenal (HPA) axis recovery.

METHODS

We review the literature on the pathogenesis of GWS and its clinical presentation. We provide strategies for glucocorticoid dosing and tapering, HPA axis testing, as well as pharmacotherapy and ancillary treatments for GWS symptom management.

RESULTS

GWS can be difficult to differentiate from adrenal insufficiency and CS recurrence, which complicates glucocorticoid dosing and tapering regimens. Monitoring for HPA axis recovery requires both clinical and biochemical assessments. The most important intervention is reassurance to patients that GWS symptoms portend a favorable prognosis of sustained remission from CS, and GWS typically resolves as the HPA axis recovers. GWS also occurs during medical management of CS, and gradual dose titration based primarily on symptoms is essential to maintain adherence and to eventually achieve disease control. Myopathy and neurocognitive dysfunction can be chronic complications of CS that do not completely recover.

CONCLUSIONS

Due to limited data, no guidelines have been developed for management of GWS. Nevertheless, this article provides overarching themes derived from published literature plus expert opinion and experience. Future studies are needed to better understand the pathophysiology of GWS to guide more targeted and optimal treatments.

Current approach of primary bilateral adrenal hyperplasia

PURPOSE OF REVIEW

To discuss the most recent findings on the pathophysiology, the genetic and molecular causes of primary bilateral adrenal hyperplasia (PBAH). The diagnostic approach of patients with PBAH will also be presented in detail with an emphasis on the emerging diagnostic tools and finally, the treatment of PBAH will be discussed with an emphasis on the newest surgical and medical treatment approaches.

RECENT FINDINGS

PBAH is a highly heterogeneous condition mostly detected incidentally on abdominal imaging. Based on the size of the nodules, PBAH is subdivided into primary bilateral macronodular adrenal hyperplasia (PBMAH) and micronodular adrenal hyperplasia. A substantial proportion of patients with PBMAH harbor a germline mutation of the armadillo repeat containing 5 tumor suppression gene and therefore genetic testing is strongly recommended. Measurements of plasma or urinary multisteroid profiles show promising results in that PBMAH has a distinctive plasma steroid fingerprint that can help in diagnosis and subtyping of PBMAH. Finally, although surgery is the mainstay of treatment of patients with PBAH, medical therapy is increasingly emerging as an alternative option.

SUMMARY

PBAH is a poorly studied and therefore a challenging disease to diagnose and treat. Hopefully with these newest diagnostic and therapeutic tools, a more comprehensive approach will be adopted.

Current and Emerging Medical Therapies in Pituitary Tumors

Pituitary tumors (PT) represent in, the majority of cases, benign tumors for which surgical treatment still remains, except for prolactin-secreting PT, the first-line therapeutic option. Nonetheless, the role played by medical therapies for the management of such tumors, before or after surgery, has evolved considerably, due in part to the recent development of well-tolerated and highly efficient molecules. In this review, our aim was to present a state-of-the-art of the current medical therapies used in the field of PT and the benefits and caveats for each of them, and further specify their positioning in the therapeutic algorithm of each phenotype. Finally, we discuss the future of PT medical therapies, based on the most recent studies published in this field.

Perioperative Management of a Patient with Cushing’s Disease

Patients with Cushing’s disease (CD) may present with both chronic and acute perioperative complications that necessitate multidisciplinary care. This review highlights several objectives for these patients before and after transsphenoidal surgery. Preoperative management includes treatment of electrolyte disturbances, cardiovascular comorbidities, prediabetes/diabetes, as well as prophylactic consideration(s) for thromboembolism and infection(s). Preoperative medical therapy (PMT) could prove beneficial in patients with severe hypercortisolism or in cases of delayed surgery. Some centers use PMT routinely, although the clinical benefit for all patients is controversial. In this setting, steroidogenesis inhibitors are preferred because of rapid and potent inhibition of cortisol secretion. If glucocorticoids are not used perioperatively, an immediate remission assessment postoperatively is possible. However, perioperative glucocorticoid replacement is sometimes necessary for clinically unstable or medically pretreated patients and for those patients with surgical complications. A nadir serum cortisol &lt; 2-5µg/dl during 24-74 hours postoperatively is generally accepted as remission; higher values suggest non-remission, while a few patients may display delayed remission. If remission is not achieved, additional treatments are pursued. The early postoperative period necessitates multidisciplinary awareness for early diagnosis of adrenal insufficiency (AI) to avoid adrenal crisis, which may be also potentiated by acute postoperative complications. Preferred glucocorticoid replacement is hydrocortisone, if available. Assessment of recovery from postoperative AI should be undertaken periodically. Other postoperative targets include decreasing antihypertensive/diabetic therapy if in remission, thromboprophylaxis, infection prevention/treatment, and management of electrolyte disturbances and/or potential pituitary deficiencies. Evaluation of recovery of thyroid, gonadal and growth hormone deficiencies should be also performed in the following months postoperatively.

Metyrapone Versus Osilodrostat in the Short-Term Therapy of Endogenous Cushing's Syndrome: Results From a Single Center Cohort Study

BACKGROUND

Although surgery is considered the first-line treatment for patients with endogenous Cushing's syndrome (CS), medical therapy is often required to control severe hypercortisolism. Metyrapone and osilodrostat are both steroidogenic inhibitors targeting the 11β-hydroxylase, however, their therapeutic effectiveness has not yet been directly compared. This study aimed to evaluate metyrapone and osilodrostat in the short-term therapy of CS.

METHODS

Retrospective analysis of patients with endogenous CS treated with metyrapone or osilodrostat as monotherapy for at least 4 weeks. Main outcome measures were serum cortisol and 24h urinary free cortisol (UFC) at baseline (T0) and after 2 (T1), 4 (T2), and 12 weeks (T3) of therapy.

RESULTS

16 patients with endogenous CS were identified (pituitary n=7, adrenal n=4, ectopic CS n=5). Each 8 patients were treated with metyrapone and osilodrostat. Despite heterogeneity, both groups showed comparable mean UFC levels at T0 (metyrapone: 758 µg/24h vs osilodrostat: 817 µg/24h; p=0.93). From T0 to T1, the decrease of UFC was less pronounced under metyrapone than osilodrostat (-21.3% vs -68.4%; median daily drug dose: 1000 mg vs 4 mg). This tendency persisted at T2 (-37.3% vs -50.1%; median drug dose: 1250 mg vs 6 mg) while at T3 a decrease in UFC from T0 was more pronounced in the metyrapone group (-71.5% vs -51.5%; median dose 1250 mg vs 7 mg). Under osilodrostat, a QTc-interval prolongation was identified at T3 (mean 432 ms vs 455 ms). From T0 to T2, the number of antihypertensive drugs remained comparable under metyrapone and decreased under osilodrostat (n= -0.3 vs n= -1.0).

CONCLUSION

Although both drugs show comparable therapeutic efficacy, osilodrostat seems to reduce cortisol levels and to control blood pressure faster.

Ketoconazole- and Metyrapone-Induced Reductions on Urinary Steroid Metabolites Alter the Urinary Free Cortisol Immunoassay Reliability in Cushing Syndrome

INTRODUCTION

Twenty-four-hour urinary free cortisol (24h-UFC) is the most used test for follow-up decision-making in patients with Cushing syndrome (CS) under medical treatment. However, 24h-UFC determinations by immunoassays (IA) are commonly overestimated because of steroid metabolites' cross-reaction. It is still uncertain how ketoconazole (KTZ)- and metyrapone (MTP)-induced changes on the urinary steroid metabolites can alter the 24h-UFC*IA determinations' reliability.

METHODS

24h-UFC was analyzed by IA and gas chromatography-mass spectrometry (GC-MS) in 193 samples (81 before treatment, 73 during KTZ, and 39 during MTP) from 34 CS patients. In addition, urinary steroidome was analyzed by GC-MS on each patient before and during treatment.

RESULTS

Before treatment, 24h-UFC*IA determinations were overestimated by a factor of 1.75 (95% CI 1.60-1.94) compared to those by GC-MS. However, during KTZ treatment, 24h-UFC*IA results were similar (0.98:1) to those by GC-MS (95% CI, 0.83-1.20). In patients taking MTP, IA bias only decreased 0.55, resulting in persistence of an overestimation factor of 1.33:1 (95% CI, 1.09-1.76). High method agreement between GC-MS and IA before treatment (R² = 0.954) declined in patients under KTZ (R² = 0.632) but not in MTP (R² = 0.917). Upper limit normal (ULN) reductions in patients taking KTZ were 27% larger when using 24h-UFC*IA compared to 24h-UFC*GC-MS, which resulted in higher false efficacy and misleading biochemical classification of 15% of patients. Urinary excretion changes of 22 urinary steroid metabolites explained 86% of the 24h-UFC*IA interference. Larger urinary excretion reductions of 6β-hydroxy-cortisol, 20α-dihydrocortisol, and 18-hydroxy-cortisol in patients with KTZ elucidated the higher 24h-UFC*IA bias decrement compared to MTP-treated patients.

CONCLUSION

KTZ and MTP alter the urinary excretion of IA cross-reactive steroid metabolites, thus decreasing the cross-reactive interference of 24h-UFC*IA determinations present before treatment. Consequently, this interference reduction in 24h-UFC*IA leads to loss of method agreement with GC-MS and high risk of overestimating the biochemical impact of KTZ and MTP in controlling CS because of poor reliability of reference ranges and ULN.

Consensus on diagnosis and management of Cushing's disease: a guideline update

Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

Management and Medical Therapy of Mild Hypercortisolism

Mild hypercortisolism (mHC) is defined as an excessive cortisol secretion, without the classical manifestations of clinically overt Cushing's syndrome. This condition increases the risk of bone fragility, neuropsychological alterations, hypertension, diabetes, cardiovascular events and mortality. At variance with Cushing's syndrome, mHC is not rare, with it estimated to be present in up to 2% of individuals older than 60 years, with higher prevalence (up to 10%) in individuals with uncontrolled hypertension and/or diabetes or with unexplainable bone fragility. Measuring cortisol after a 1 mg overnight dexamethasone suppression test is the first-line test for searching for mHC, and the degree of cortisol suppression is associated with the presence of cortisol-related consequences and mortality. Among the additional tests used for diagnosing mHC in doubtful cases, the basal morning plasma adrenocorticotroph hormone, 24-h urinary free cortisol and/or late-night salivary cortisol could be measured, particularly in patients with possible cortisol-related complications, such as hypertension and diabetes. Surgery is considered as a possible therapeutic option in patients with munilateral adrenal incidentalomas and mHC since it improves diabetes and hypertension and reduces the fracture risk. In patients with mHC and bilateral adrenal adenomas, in whom surgery would lead to persistent hypocortisolism, and in patients refusing surgery or in whom surgery is not feasible, medical therapy is needed. Currently, promising though scarce data have been provided on the possible use of pituitary-directed agents, such as the multi-ligand somatostatin analog pasireotide or the dopamine agonist cabergoline for the-nowadays-rare patients with pituitary mHC. In the more frequently adrenal mHC, encouraging data are available for metyrapone, a steroidogenesis inhibitor acting mainly against the adrenal 11-βhydroxylase, while data on osilodrostat and levoketoconazole, other new steroidogenesis inhibitors, are still needed in patients with mHC. Finally, on the basis of promising data with mifepristone, a non-selective glucocorticoid receptor antagonist, in patients with mild cortisol hypersecretion, a randomized placebo-controlled study is ongoing for assessing the efficacy and safety of relacorilant, a selective glucocorticoid receptor antagonist, for patients with mild adrenal hypercortisolism and diabetes mellitus/impaired glucose tolerance and/or uncontrolled systolic hypertension.

Effectiveness of Medical Treatment of Cushing's Disease: A Systematic Review and Meta-Analysis

Objective

The objective of this systematic review was to evaluate the effectiveness and safety of pasireotide, cabergoline, ketoconazole, levoketoconazole, metyrapone, osilodrostat, and temozolomide for the treatment of Cushing's disease (CD).

Methods

The primary outcomes were the proportion of CD control, adverse events (AE), and reduction of urinary free cortisol. Search strategies were applied to Embase, Medline, and CENTRAL. Independent reviewers assessed the study eligibility, extracted data, and evaluated risk of bias. Standardized mean difference was calculated with 95% confidence interval (CI) for continuous data (i.e., pre- and post-intervention). Random meta-analyses for the proportion of CD control and AE were conducted.

Results

Twenty-nine controlled and non-controlled studies were included. No study with temozolomide and levoketoconazole and one study with osilodrostat fulfilled the inclusion criteria. The meta-analyses of proportion of CD control was 35% for cabergoline (95% CI: 27-43%, six studies, 141 participants), 44% for pasireotide (95% CI: 25-35%, eight studies, 522 participants), 41% for ketoconazole (95% CI: 36-46%, six studies, 450 participants), 66% for metyrapone (95% CI: 46-87%, four studies, 66 participants), and of 66.4% for osilodrostat (95% CI: 57.9, 74.3, 97 participants, one study). One study compared two different treatments (cabergoline vs. ketoconazole), and no statistical difference was observed in CD control (RR: 0.53, 95% CI: 0.15 to 1.87, 14 participants, very low certainty of evidence). The most frequent AE associated with pasireotide was hyperglycemia, dizziness and nausea with cabergoline and metyrapone, and elevated transaminases with ketoconazole.

Conclusion

The superiority of one drug over another could not be determined due to lack of controlled studies, but the proportion of disease control identified in our meta-analysis may support clinical decision. New therapeutic options should be investigated due to the limited efficacy and tolerability of the currently available medical treatment for patients with Cushing's disease.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020205567, identifier CRD42020205567.

Updates in adrenal steroidogenesis inhibitors for Cushing's syndrome - A practical guide

Medical therapy is essential in the management of patients with Cushing's syndrome (CS) when curative surgery has failed, surgery is not feasible, when awaiting radiation effect, and in recurrent cases of CS. Steroidogenesis inhibitors have a rapid onset of action and are effective in reducing hypercortisolism, however, adverse effects, including adrenal insufficiency require very close patient monitoring. Osilodrostat is the only steroidogenesis inhibitor to have been assessed in prospective randomized controlled trials and approved for Cushing's disease (CD) by the US Food and Drug Administration and for CS by the European Medical Agency (EMA). Osilodrostat has been shown to be highly effective at maintaining normal urinary free cortisol in patients with CD. Drugs such as metyrapone, ketoconazole (both EMA approved), and etomidate lack prospective evaluation(s). There is, however, considerable clinical experience and retrospective data that show a very wide efficacy range in treating patients with CS. In the absence of head-to-head comparative clinical trials, therapy choice is determined by the specific clinical setting, risk of adverse events, cost, availability, and other factors. In this review practical points to help clinicians who are managing patients with CS being treated with steroidogenesis inhibitors are presented.

Management of patients with persistent or recurrent Cushing's disease after initial pituitary surgery

INTRODUCTION

Treatment options for persistent and recurrent Cushing's disease (CD) include an individualized approach for repeat surgery, medical treatment, radiation therapy (RT), and bilateral adrenalectomy (BLA).

AREAS COVERED

In this expert opinion perspective, the authors review the latest treatment(s) for persistent/recurrent CD. A PubMed search was undertaken (English articles through May 2020) and relevant articles discussed. Repeat pituitary surgery should be considered in most patients with proven hypercortisolism; there is potential for cure with low risk of major complications. Medical therapy is valuable either alone, while awaiting the effects of RT, or in preparation for BLA. Medical therapy includes steroidogenesis inhibitors, agents that act at the pituitary or glucocorticoid receptor level, and novel agents in development. Radiation therapy has been used successfully to treat CD, but hypopituitarism risk and delayed efficacy (improved with radiosurgery) are major drawbacks. Laparoscopic BLA is safe and effective in patients with severe, difficult-to-manage hypercortisolism, but long-term follow-up is required as corticotroph tumor progression can develop.

EXPERT OPINION

Treatment of persistent/recurrent CD is challenging. Most patients require >1 therapy to achieve long-lasting remission. There is currently no ideal single treatment option that provides high and rapid efficacy, low adverse effects, and preserves normal pituitary-adrenal axis function.

What is the role of medical therapy in adrenal-dependent Cushing's syndrome?

Medical therapy to control hypercortisolism in adrenal Cushing's syndrome is currently not the first-line therapy. However, in many clinical scenarios like pre-surgical treatment, in patients who are not suitable candidates for surgery or in patients with bilateral hyperplasia, medical therapy can be important representing the only viable treatment option. Adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers have been used for many years: metyrapone, ketoconazole and mifepristone are in current use and effective. Mitotane can be used as well but is considered second-line therapy because of its high toxicity. Etomidate has a special position as emergency medication in severe hypercortisolism. New drugs are tested in prospective trials (levoketoconazole, osilidrostat and relacorilant) and might become effective alternatives to common drugs. Oher drugs - adrenal steroidogenesis inhibitors as well as glucocorticoid receptor antagonists - are currently tested in vitro.

Medical Treatment of Cushing's Disease: An Overview of the Current and Recent Clinical Trials

Cushing's disease (CD) is a serious endocrine disorder characterized by chronic hypercortisolism, or Cushing's syndrome (CS), caused by a corticotroph pituitary tumor, which induces an excessive adrenocorticotropic hormone (ACTH) and consequently cortisol secretion. CD presents a severe clinical burden, with impairment of the quality of life and increase in mortality. Pituitary surgery represents the first-line therapy, but it is non-curative in one third of patients, requiring additional treatments. Among second-line treatments, medical therapy is gradually gaining importance, although the current medical treatments are unable to reach optimal efficacy and safety profile. Therefore, new drugs and new formulations of presently available drugs are currently under clinical investigation in international clinical trials, in order to assess their efficacy and safety in CD, or in the general population of CS. Among pituitary-directed agents, pasireotide, in the twice-daily subcutaneous formulation, has been demonstrated to be an effective treatment both in clinical trials and in real-world studies, and extension studies of the phase II and III clinical trials reported evidence of long-term efficacy with general good safety profile, although associated with frequent hyperglycemia, which requires monitoring of glucose metabolism. Moreover, the most recent once-monthly intramuscular formulation, pasireotide long-acting release (LAR), showed similar efficacy and safety, but associated with potential better compliance profile in CD. Roscovitine is an experimental drug currently under investigation. Among adrenal-directed agents, metyrapone is the only historical agent currently under investigation in a prospective, multicenter, international clinical trial, that would likely clarify its efficacy and safety in a large population of patients with CS. Osilodrostat, a novel agent with a mechanism of action similar to metyrapone, seems to offer a rapid, sustained, and effective disease control of CD, according to recently completed clinical trials, whereas levoketoconazole, a different chemical formulation of the historical agent ketoconazole, is still under investigation in clinical trials, with preliminary evidences showing an effective and safe control of CS. ATR-101 is an experimental drug currently under investigation. Among glucocorticoid receptor-directed drugs, mifepristone has been demonstrated to improve clinical syndrome and comorbidities, especially hypertension and impairment of glucose metabolism, but the occurrence of hypokalemia and in women uterine disorders, due to the concomitant action on progestin receptor, requires caution, whereas the preliminary evidence on relacorilant, characterized by high selectivity for glucocorticoid receptor, suggested good efficacy in the control of hypertension and impairment of glucose metabolism, as well as a good safety profile, in CS. Finally, a limited experience has demonstrated that combination therapy might be an interesting approach in the management of CD. The current review provides a summary of the available evidences from current and recent clinical trials on CD, with a specific focus on preliminary data.

Medical Management of Cushing's Syndrome: Current and Emerging Treatments

Endogenous Cushing's syndrome is a chronic disease associated with increased morbidity and mortality if not appropriately treated. Recurrence and/or persistence of hypercortisolemia after surgical treatment, especially for Cushing's disease, are high, and long-term medical treatment is used to decrease cortisol levels and risk of metabolic comorbidities. Medical treatment is also often required while waiting for radiation effects to take place. In some cases, severe or life-threatening hypercortisolism must be urgently and medically treated, via intravenous medications or with combination therapy, before patients can undergo surgery. In the last decade, medical treatment has progressed from a few steroidogenesis inhibitors to three novel drug groups: new inhibitors for steroidogenic enzymes with possibly fewer side effects, pituitary-directed drugs that aim to inhibit the pathophysiological pathways of Cushing's disease, and glucocorticoid receptor antagonists that block cortisol's action. Understanding the pathophysiology of Cushing's syndrome has also led to the identification of potential targets that may decrease adrenocorticotrophic hormone and/or cortisol excess, and/or decrease tumor cell proliferation, and induce senescence or apoptosis. We provide here a review of current and near-future medical options to treat Cushing's syndrome, and discuss updates on clinical trials and the efficacy and safety of novel or in-development drugs, as well as future potential targets.

The Pathophysiology and Treatment of Hypertension in Patients With Cushing's Syndrome

When hypertension, a pathology that is frequently found in the general population, presents in a young patient, secondary causes such as Cushing's syndrome (CS), a rare disease characterized by long-term elevated cortisol levels, should be considered. Present in ~80% of CS patients independently of their age and sex, hypertension is one of the pathology's most prevalent, alarming features. Its severity is principally associated with the duration and intensity of elevated cortisol levels. Prompt diagnosis and rapid initiation of treatment are important for reducing/delaying the consequences of hypercortisolism. Glucocorticoid excess leads to hypertension via a variety of mechanisms including mineralocorticoid mimetic activity, alterations in peripheral and renovascular resistance, and vascular remodeling. As hypertension in CS patients is caused by cortisol excess, treating the underlying pathology generally contributes to reducing blood pressure (BP) levels, although hypertension tends to persist in approximately 30% of cured patients. Surgical removal of the pituitary tumor remains the first-line treatment for both adrenocorticotropin hormone (ACTH) dependent and independent forms of the syndrome. In light of the fact that surgery is not always successful in curing the underlying disease, it is essential that other treatments be considered and prescribed as needed. This article discusses the mechanisms involved in the pathogenesis of CS and the pros and the cons of the various antihypertensive agents that are presently available to treat these patients.

Glucocorticoid Receptor Antagonist Administration Prevents Adrenal Gland Atrophy in an ACTH-Independent Cushing's Syndrome Rat Model

ACTH-independent Cushing's syndrome (CS) is mainly caused by cortisol-secreting adrenocortical tumours. It is well known that secondary adrenal insufficiency occurs after surgical resection of these tumours. In this regard, impaired adrenocortical function is likely induced by atrophy of the residual adrenal tissue as a result of chronic suppression by the low ACTH levels of the hypercortisolism state. Therefore, we considered the prevention of adrenal atrophy as a method for preventing postoperative adrenal insufficiency. On the basis of these findings, we hypothesized that the use of a glucocorticoid receptor (GR) antagonist before surgery in ACTH-independent CS would rapidly activate the hypothalamic-pituitary-adrenal (HPA) axis and residual adrenal function. We thus examined adrenal function in a dexamethasone- (DEX-) induced CS rat model with or without mifepristone (MIF). In this study, MIF-treated rats had elevated plasma ACTH levels and increased adrenal weights. In addition, we confirmed that there were fewer atrophic changes, as measured by the pathological findings and mRNA expression levels of corticosterone synthase CYP11B1 in the adrenal glands, in MIF-treated rats. These results indicate that MIF treatment prevents the suppression of the HPA axis and the atrophy of the residual adrenal tissue. Therefore, our study suggests that preoperative GR antagonist administration may improve residual adrenal function and prevent postoperative adrenal insufficiency in ACTH-independent CS.

Drug design strategies for Cushing's syndrome

INTRODUCTION

Cushing's syndrome (CS) is a metabolic disorder caused by chronic hypercortisolism. CS is associated with cardiovascular, metabolic, skeletal and psychological dysfunctions and can be fatal if left untreated. The first-line treatment for all forms of CS is a surgery. However, medical therapy has to be chosen if surgical resection is not an option or is deemed ineffective. Currently available therapeutics are either not selective and have side effects or are only available as an injection (pasireotide). Areas covered: The authors discuss the recent drug developments for the medical treatment of CS through two validated molecular targets. Specifically, the authors look at selective inhibitors of CYP11B1 that reduce cortisol production by inhibiting steroid 11beta-hydroxylase and glucocorticoid receptor (GR) antagonists that interrupt cortisol-mediating transcriptional regulation of related genes. Expert opinion: Patients with CS have limited treatment options; indeed, there is an unmet need for new compounds that target CYP11B1 selectively versus several steroidogenic enzymes and/or GR-signaling pathways. The complexity of steroid biosynthesis and signaling requires the application of structure-based drug discovery techniques that use molecular targets and highly similar off-targets. Significant differences in steroidogenesis between humans and other species necessitates caution over the choice of in vivo model for the preclinical evaluation of future potential compounds.