Cabergoline for Cushing's disease: a large retrospective multicenter study

Medical Treatment of Cushing's Syndrome

Endogenous Cushing's syndrome (CS) refers to the manifestations of chronic cortisol excess. This rare disease is associated with multiple comorbidities, impaired quality of life, and increased mortality. The management of CS remains challenging. Regardless of the underlying cause, surgical resection of the tumor is typically the first-line and preferred treatment. However, when surgery is not feasible or has been unsuccessful, medical therapies may be employed to control CS. The therapeutic strategy should be individualized based on the recommendations of a multidisciplinary team of experts and the patient's preferences, informed by detailed information on the available options. All medications require careful monitoring, along with adequate instructions for patients and caregivers. The aim of this mini-review is to provide an overview of the main medical therapies currently used to treat CS, including their efficacy, safety, and management. Despite the availability of new drugs in recent years, the need remains for more effective specific targeted pharmacological therapies.

Medical management pathways for Cushing's disease in pituitary tumors centers of excellence (PTCOEs)

PURPOSE

A recent update of consensus guidelines for the management of Cushing's disease (CD) included indications for medical therapy. However, there is limited evidence regarding their implementation in clinical practice. This study aimed to evaluate current medical therapy approaches by expert pituitary centers through an audit conducted to validate the criteria of Pituitary Tumors Centers of Excellence (PTCOEs) and provide an initial standard of medical care for CD.

METHODS

Based on the activities of nine international PTCOEs between 2018 and 2020, we evaluated patients under medical treatment and their biochemical control rates.

RESULTS

The median number of active patients with CD per center was 117 (35-279), with a median number of 10 new patients with CD managed annually in the endocrinology units of PTCOEs (4-42). The median percentage of patients with CD receiving medical treatment was 13.3% (4.8-82.9). Ketoconazole was the most frequently used drug, with a median rate of usage of 26.5% (5-66.7) of those receiving medical therapy. The median rates of metyrapone and pasireotide use were 17.2% (0-50) and 9.3% (0-51.7), respectively. For cabergoline and osilodrostat, therapy, the median rates of use were 2.8% (0-33.3), and 1.7% (0-25), respectively. Combination therapy was reported to be utilized in 13.6% (0-45.5) of medically treated patients. Mifepristone was used in a single center, representing 1.1% of its medically treated patients. Overall, the median control rate in patients with CD receiving medical treatment was 75% (10-100).

CONCLUSION

Adrenal steroidogenesis inhibitors were the most commonly used medications amongst the centers. Despite the use of combination therapy, up to 25% of patients did not achieve disease control even in PTCOEs, highlighting the need for either more efficient combination therapies or novel therapeutic options.

Cushing syndrome

Cushing syndrome (CS) is a constellation of signs and symptoms caused by excessive exposure to exogenous or endogenous glucocorticoid hormones. Endogenous CS is caused by increased cortisol production by one or both adrenal glands (adrenal CS) or by elevated adrenocorticotropic hormone (ACTH) secretion from a pituitary tumour (Cushing disease (CD)) or non-pituitary tumour (ectopic ACTH secretion), which stimulates excessive cortisol production. CS is associated with severe multisystem morbidity, including impaired cardiovascular and metabolic function, infections and neuropsychiatric disorders, which notably reduce quality of life. Mortality is increased owing to pulmonary emboli, infection, myocardial infarction and cerebrovascular accidents. The clinical presentation is variable and because some CS signs and symptoms are common in the general population, the diagnosis might not be considered until many features have accumulated. Guidelines recommend screening patients with suspected CS with 24-h urine cortisol, bedtime salivary cortisol and/or 1 mg dexamethasone suppression test. Subsequently, determining the aetiology of CS is important as it affects management. The first-line therapy for all aetiologies of endogenous CS is surgical resection of the causal tissue, including corticotroph adenoma or ectopic tumour for ACTH-dependent CS or unilateral or bilateral adrenalectomy for adrenal CS. Second-line therapies include steroidogenesis inhibitors for any cause of CS, pituitary radiation (with or without steroidogenesis inhibitors) for CD, and bilateral adrenalectomy for ACTH-dependent causes of CS.

New Approaches to the Treatment of Hypercortisolism

This review explores the evolving landscape of treatments for hypercortisolism, highlighting both established and emerging therapies. Although surgery remains the cornerstone of management, medical therapies play a crucial and expanding role, especially in cases of persistent, recurrent, or severe hypercortisolism. We discuss the effectiveness and limitations of steroidogenesis inhibitors, pituitary-directed drugs, glucocorticoid receptor antagonists, and experimental drugs targeting novel molecular pathways that have been implicated in the pathogenesis of hypercortisolism. Despite advancements, significant unmet needs persist, underscoring the importance of personalized treatment approaches and the development of targeted therapies. Ongoing and future clinical trials are crucial for validating the safety and efficacy of these innovative treatments in Cushing disease management.

Improved Clinical Outcomes During Long-term Osilodrostat Treatment of Cushing Disease With Normalization of Late-night Salivary Cortisol and Urinary Free Cortisol

Purpose

To assess whether simultaneous normalization of late-night salivary cortisol (LNSC) and mean urinary free cortisol (mUFC) in patients with Cushing disease treated with osilodrostat is associated with better clinical outcomes than control of mUFC or LNSC alone.

Methods

Pooled data from two phase III osilodrostat studies (LINC 3 and LINC 4) were analyzed. Both comprised a 48-week core phase and an optional open-label extension. Changes in cardiovascular/metabolic-related parameters, physical manifestations of hypercortisolism, and quality of life (QoL) were evaluated across the following patient subgroups: both LNSC and mUFC controlled, only mUFC controlled, only LNSC controlled, and neither controlled.

Results

Of 160 patients included in the analysis, 85.0% had both LNSC and mUFC uncontrolled at baseline. At week 72, 48.6% of patients had both LNSC and mUFC controlled; these patients generally exhibited greater improvements in cardiovascular/metabolic-related parameters than those with only mUFC controlled or both LNSC and mUFC uncontrolled: systolic/diastolic blood pressure, -7.4%/-4.9%, -6.0%/-5.5%, and 2.3%/0.8%, respectively; fasting plasma glucose, -5.0%, -4.8%, and 1.9%; glycated hemoglobin, -5.1%, -4.8%, and -1.3%. Weight, waist circumference, and body mass index improved with control of LNSC and/or mUFC; physical manifestations of hypercortisolism generally improved regardless of LNSC/mUFC control. Patients with both LNSC and mUFC controlled or only mUFC controlled had the greatest improvement from baseline to week 72 in QoL.

Conclusion

In osilodrostat-treated patients with Cushing disease, normalization of LNSC and mUFC led to improvements in long-term outcomes, indicating that treatment should aim for normalization of both parameters for optimal patient outcomes.

Clinical trial identifiers

NCT02180217 (LINC 3); NCT02697734 (LINC 4).

Aberrant hormone receptors regulate a wide spectrum of endocrine tumors

Aberrant G-protein coupled receptor (GPCR) expression is highly prevalent in cortisol-secreting primary bilateral macronodular adrenal hyperplasia (PBMAH) and unilateral adenomas. The aberrant expression of diverse GPCRs and their ligands play an important role in the over-function of various endocrine tumours. Examples include aberrant expression of MC2R, 5-HT4R, AVPR1A, LHCGR, and GnRHR in primary aldosteronism; GCGR, LHCGR, and 5-HT4R in phaeochromocytomas and paragangliomas; TRHR, GnRHR, GIPR, and GRP101 in pituitary somatotroph tumours; AVPR2, D2DR, and SSTR5 in pituitary corticotroph tumours; GLP1R, GIPR, and somatostatin receptors in medullary thyroid carcinoma; and SSTRs, GLP1R, and GIPR in other neuroendocrine tumours. The genetic mechanisms causing the ectopic expression of GIPR in cortisol-secreting PBMAHs and unilateral adenomas have been identified, but distinct mechanisms are implicated in other endocrine tumours. Development of functional imaging targeting aberrant GPCRs should be useful for identification and for specific therapies of this wide spectrum of tumours. The aim of this review is to show that the regulation of endocrine tumours by aberrant GPCR is not restricted to cortisol-secreting adrenal lesions, but also occurs in tumours of several other organs.

From Nelson's Syndrome to Corticotroph Tumor Progression Speed: An Update

Since the first description of Nelson syndrome 60 years ago, the way to consider corticotroph pituitary neuroendocrine tumors (PitNETs) after bilateral adrenalectomy has evolved. Today, it is globally acknowledged that only a subset of corticotroph PitNETs is aggressive.After adrenalectomy, corticotroph tumor progression (CTP) occurs in about 30 to 40% of patients during a median follow-up of 10 years. When CTP occurs, various CTP speeds (CTPS) can be observed. Using simple metrics in patients with CTP, CTPS was reported to vary from a few millimeters to up to 40 mm per year. Rapid CTPS/ Nelson's syndrome was associated with more severe Cushing's disease, higher adrenocorticotropic hormone (ACTH) in the year following adrenalectomy, and higher Ki67 on pituitary pathology. Complications such as apoplexy, cavernous syndrome, and visual defects were associated with higher CTPS. During follow-up, early morning ACTH, absolute variations properly reflected CTPS. Finally, CTPS was not higher after than before adrenalectomy, suggesting that cortisol deprivation after adrenalectomy does not impact CTPS in a majority of patients.Taken together, rapid CTPS/ Nelson's syndrome probably reflects the intrinsic aggressiveness of some corticotroph PitNETs. The precise molecular mechanisms related to corticotroph PitNET aggressiveness remain to be deciphered. Regular MRIs combined with intermediate morning ACTH measurements probably provide a reliable way to detect early and manage fast-growing tumors and, therefore, limit the complications.

The effects of cabergoline in the presurgical and recurrence periods of Cushing's disease patients

BACKGROUND

The dopaminergic agonist cabergoline (CAB) has been used in the pharmacological treatment of Cushing's disease (CD). The effect is attributed to the frequent expression of the dopamine receptor subtype 2 in corticotroph tumors. However, in-vivo studies have demonstrated the normalization of 24-h urinary cortisol (24-h UC) in approximately 30-40% of patients over the long term, mainly after surgical failure. The aim was to evaluate the effect of CAB as monotherapy in the early preoperative period and on the recurrence of CD.

METHODS

A single-center retrospective study was conducted in a tertiary referral center. Twenty-one patients with confirmed CD were included. The median age was 32 years (13-70), 86% were female, 10 had microadenomas, and 11 had macroadenomas. They were diagnosed from 1986 to 2016 and used CAB as monotherapy either in the preoperative period (N.=7, CABi) or upon recurrence before any other treatment (N.=14, CABr). A "complete response" was considered 24-h UC normalization and a "partial response" was considered a 24-h UC reduction of >50%. UC was obtained at the last follow-up evaluation. The normalization of late-night salivary cortisol (LNSC) after CAB use was evaluated in most patients, as well as the tumor diameter by pituitary MRI, before and after CAB treatment.

RESULTS

Complete response was achieved in 29% (6/21) of subjects after 14.9±16.4 months of treatment, with an average dose of 2.2±1.0 mg/week. Partial response occurred in 9.5% (2/21). LNSC normalized in 35% (6/17) of patients, and no variation in tumor diameter before and after CAB use was observed (N.=13): 6.8±6.8 vs. 7.2±7.1 mm. There was no normalization of 24-h-UC in the CABi subgroup at the end of the treatment, whereas 43% (6/14) of patients in the CABr subgroup reached complete response. The CABi subgroup was treated for 4.7±1.9 months, and the CABr subgroup was treated for 20.1±18.1 months. Both groups were administered similar doses of CAB (CABi 2.1±0.9 and CABr 2.3±1.1 mg/week). Interestingly, the difference between the subgroups' complete response was evident early on in the three months of treatment: no patients in the CABi subgroup vs. 6/10 (60%) in the CABr subgroup (P=0.035), despite a lower dose in the CABr subgroup (1.1 vs. 1.6; P=0.008). The normalization of LNSC occurred in 20% of the CABi subgroup and in 42% of the CABr subgroup.

CONCLUSIONS

The normalization of 24-h UC and LNSC occurred in approximately 30% of all patients, mainly in those who used CAB for the recurrence of CD. Despite the small number of subjects in the CABi subgroup, the absence of hormone control in this subgroup discourages the use of this medication as primary therapy or as a preoperative treatment option.

How to manage Cushing's disease after failed primary pituitary surgery

The first-line treatment for Cushing's disease is transsphenoidal adenomectomy, which can be curative in a significant number of patients. The second-line options in cases of failed primary pituitary surgery include repeat surgery, medical therapy, and radiation. The role for medical therapy has expanded in the last decade, and options include pituitary-targeting drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. Bilateral adrenalectomy is a more aggressive approach, which may be necessary in cases of persistent hypercortisolism despite surgery, medical treatment, or radiation or when rapid normalization of cortisol is needed. We review the available treatment options for Cushing's disease, focusing on the second-line treatment options to consider after failed primary pituitary surgery.

Neurochemical Anatomy of Cushing's Syndrome

The neurochemical anatomy underlying Cushing's syndrome is examined for regional brain metabolism as well as neurotransmitter levels and receptor binding of biogenic amines and amino acids. Preliminary studies generally indicate that glucose uptake, blood flow, and activation on fMRI scans decreased in neocortical areas and increased in subcortical areas of patients with Cushing's syndrome or disease. Glucocorticoid-mediated increases in hippocampal metabolism occurred despite in vitro evidence of glucocorticoid-induced decreases in glucose uptake or consumption, indicating that in vivo increases are the result of indirect, compensatory, or preliminary responses. In animal studies, glucocorticoid administration decreased 5HT levels and 5HT1A receptor binding in several brain regions while adrenalectomy increased such binding. Region-specific effects were also obtained in regard to the dopaminergic system, with predominant actions of glucocorticoid-induced potentiation of reuptake blockers and releasing agents. More in-depth neuroanatomical analyses are warranted of these and amino acid-related neurotransmission.

Budget impact analysis of cabergoline for medical treatment of Cushing's disease in Brazil

Objective

The aim of this study was to estimate the budget impact of adding cabergoline to the Brazilian Unified Health System (SUS) formulary for the treatment of patients with Cushing's disease (CD) who do not achieve disease control after transsphenoidal surgery.

Materials and methods

We conducted a budget impact analysis (BIA) from the perspective of the Brazilian SUS over a 5-year time horizon. We compared two scenarios: ketoconazole (Scenario 1) versus including cabergoline as a treatment option (Scenario 2). All analyses were conducted using Microsoft Excel. Uncertainty was explored in univariate sensitivity analyses.

Results

The total costs were BRL $25,596,729 for Scenario 1 and BRL $32,469,169 for Scenario 2. The budget impact of adding cabergoline to the formulary for CD treatment within the SUS would be BRL $6,091,036 over 5 years. On univariate analyses, variations in the rates of surgical failure and CD recurrence had the greatest potential to affect the final costs associated with cabergoline.

Conclusions

The estimated budget impact of adding cabergoline to the formulary for CD treatment within the Brazilian SUS would be about BRL $6 million. While cost savings cannot be expected, the budget impact of adding cabergoline would be lower than that of adding other treatment options for CD.

High-throughput Screening for Cushing Disease: Therapeutic Potential of Thiostrepton via Cell Cycle Regulation

Cushing disease is a life-threatening disorder caused by autonomous secretion of ACTH from pituitary neuroendocrine tumors (PitNETs). Few drugs are indicated for inoperative Cushing disease, in particular that due to aggressive PitNETs. To explore agents that regulate ACTH-secreting PitNETs, we conducted high-throughput screening (HTS) using AtT-20, a murine pituitary tumor cell line characterized by ACTH secretion. For the HTS, we constructed a live cell-based ACTH reporter assay for high-throughput evaluation of ACTH changes. This assay was based on HEK293T cells overexpressing components of the ACTH receptor and a fluorescent cAMP biosensor, with high-throughput acquisition of fluorescence images. We treated AtT-20 cells with compounds and assessed ACTH concentrations in the conditioned media using the reporter assay. Of 2480 screened bioactive compounds, over 50% inhibition of ACTH secreted from AtT-20 cells was seen with 84 compounds at 10 μM and 20 compounds at 1 μM. Among these hit compounds, we focused on thiostrepton (TS) and determined its antitumor effects in both in vitro and in vivo xenograft models of Cushing disease. Transcriptome and flow cytometry analyses revealed that TS administration induced AtT-20 cell cycle arrest at the G2/M phase, which was mediated by FOXM1-independent mechanisms including downregulation of cyclins. Simultaneous TS administration with a cyclin-dependent kinase 4/6 inhibitor that affected the cell cycle at the G0/1 phase showed cooperative antitumor effects. Thus, TS is a promising therapeutic agent for Cushing disease. Our list of hit compounds and new mechanistic insights into TS effects serve as a valuable foundation for future research.

Medical treatment of functional pituitary adenomas, trials and tribulations

CONTEXT

Functioning pituitary adenomas (FPAs) include most frequently prolactinomas, somatotroph or corticotroph adenomas, while thyrotroph and gonadotroph adenomas are very rare. Despite their benign histological nature (aggressive tumors are rare and malignant ones exceptional), FPAs could cause significant morbidity and increased mortality due to complications associated with hormonal excess syndromes and/or mass effect leading to compression of adjacent structures. This mini review will focus on the increasing role of medical therapy in the multimodal treatment, which also includes transsphenoidal surgery (TSS) and radiotherapy.

EVIDENCE SYNTHESIS

Most patients with prolactinomas are treated only with medications, but surgery could be considered for some patients in a specialized pituitary center, if higher chances of cure. Dopamine agonists, especially cabergoline, are efficient in reducing tumor size and normalizing prolactin. TSS is the first-line treatment for all other FPAs, but most patients require complex adjuvant treatment, including a combination of therapeutic approaches. Medical therapy is the cornerstone of treatment in all patients after unsuccessful surgery or when surgery cannot be offered and includes somatostatin receptor ligands and dopamine agonists (almost all FPAs), growth hormone receptor antagonists (acromegaly), adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers (Cushing's disease). Novel medical treatments, especially for acromegaly and Cushing's disease are under research.

CONCLUSIONS

An enlarged panel of effective drugs available with increased knowledge of predictive factors for response and/or adverse effects will enhance the possibility to offer a more individualized treatment. This would not only improve disease control and prognosis, but also quality of life.

Seliciclib: A New Treatment for Cushing's Disease?

Previous studies have suggested that corticotroph tumours are associated with the overexpression of cyclin E and that the inactivation of cyclin-dependent kinases, which activate cyclin E, may have antisecretory and antiproliferative effects. Seliciclib, also known as R-roscovitine, is a pituitary-targeting agent shown to inhibit the growth of corticotroph tumour cells via cyclin E and retinoblastoma protein-mediated pathways. A recent study investigated the role of seliciclib in regulating biochemical parameters in a small number of patients with Cushing's disease, providing preliminary data on its possible therapeutic effectiveness in treating this disorder.

Discontinuation of Drug Treatment in Cushing's Disease Not Cured by Pituitary Surgery

OBJECTIVE

When transsphenoidal surgery (TSS) does not cure Cushing's disease (CD), 4 treatments are available: drug treatment (DT), second TSS (2nd TSS), bilateral adrenalectomy (BA), and pituitary radiotherapy (PR). DT is attractive but supposes long-term continuation, which we aimed to evaluate.

DESIGN AND METHODS

Retrospective study, in a center prioritizing 2nd TSS, of 36 patients, including 19 with TSS failure and 17 with recurrence, out of 119 patients with CD treated by a first TSS, average follow-up 6.1 years (95% confidence interval 5.27-6.91). Control was defined as normalization of urinary free cortisol (UFC) and final treatment (FT) as the treatment allowing control at last follow-up. We also analyzed discontinuation rates of DT in published CD prospective clinical trials.

RESULTS

Control was achieved in 33/36 patients (92%). DT was initiated in 29/36 patients (81%), allowing at least 1 normal UFC in 23/29 patients (79%) but was discontinued before last follow-up in 18/29 patients (62%). DT was FT in 11/29 patients (38%), all treated with cortisol synthesis inhibitors. Second TSS was FT in 8/16 (50%), BA in 14/14 (100%), and PR in 0/5. In published trials, discontinuation of DT was 11% to 51% at 1 year and 32% to 74% before 5 years.

CONCLUSION

DT allowed at least 1 normal UFC in 23/29 patients (79%) but obtained long-term control in only 11/29 (38%), as discontinuation rate was high, although similar to published data. Interestingly, a successful 2nd TSS was the cause for discontinuing efficient and well-tolerated DT in 5 patients. Further studies will show whether different strategies with cortisol synthesis inhibitors may allow for a lower discontinuation rate in patients not candidates for a 2nd TSS so that BA may be avoided in these patients.

Retrospective assessment of the use of extended-release cabergoline in the management of equine pituitary pars intermedia dysfunction

Introduction

Dopaminergic agonists are accepted as the most effective treatment for pituitary pars intermedia dysfunction. However, some horses are refractory to daily oral pergolide, the recommended registered treatment. Extended-release cabergoline (ERC) injection may offer an alternative. The objective of this retrospective case series was to describe clinical and endocrinological responses to ERC.

Methods

Medical records of horses treated with weekly intramuscular injections of ERC (5 mg/mL, BOVA Aus) at either 0.01 mg/kg (high dose, HD) (n = 10) or 0.005 mg/kg (low dose, LD) (n = 30) were reviewed. Short-term ACTH responses were assessed at 5-8 days using a Wilcoxon signed ranked test. Longer-term ACTH responses (30 to 365 days) were assessed using generalised estimating equations.

Results

Five to eight days after the first dose of LDERC, median adrenocorticotropic hormone (ACTH) concentration was lower (p = 0.001), changing from 153 pg/mL (IQR: 78, 331) to 57 pg/mL (IQR: 30, 102). With HDERC, median ACTH concentration was also 153 pg/mL (IQR: 96, 185) before and then 56 pg/mL (IQR: 29, 86) after 5-8 days of treatment (p = 0.047). Over 12 months of treatment, ACTH concentration ranged from 14 to >1,250 pg/mL (median: 51 pg/mL) in horses treated with LDERC and 20 to 472 pg/mL (median: 50 pg/mL) in horses treated with HDERC. Measurements remained above the seasonal reference range in 39.3 and 52.3% of horses treated with LDERC and HDERC, respectively. Clinical improvement was reported by owners in 78.3 and 100% of horses treated with LDERC and HDERC, respectively. Partial, self-limiting inappetence was reported in 30.0% of LDERC and 60% HDERC cases. Seven horses exhibited lethargy (5 LDERC, 2 HDERC). Insulin concentrations measured 30 days post-ERC treatment were no different from baseline.

Discussion

Clinical and endocrinological responses were consistent with results of previous reports of oral pergolide treatment. Weekly injection of ERC may be an effective alternative to pergolide; the 0.005 mg/kg dose appeared to be as effective, with less risk of inappetence, than the 0.01 mg/kg dose that has been reported previously.

Case report: Complete restoration of the HPA axis function in Cushing's disease with drug treatment

This report describes a rare case of a 20-year-old man with an ACTH- and prolactin-secreting invasive pituitary macroadenoma causing hyperprolactinemia and Cushing's disease. He was later found to have an AIP mutation. Treatment with cabergoline (1.5 mg weekly) normalized prolactin concentrations and induced a major shrinkage of the adenoma. Not only was urinary free cortisol normalized for more than 14 years, but also the treatment induced normal hypothalamo-pituitary-adrenal (HPA) axis function as illustrated by the reappearance of a normal cortisol/ACTH circadian rhythm, cortisol suppression to dexamethasone, and disappearance of the excessive and aberrant responses to CRH and desmopressin, respectively. This case is the first description of complete restoration of the physiological characteristics of the HPA axis by a medication during the treatment of Cushing's disease. Although exceptional, it illustrates that drugs targeting the pituitary adenoma can bring true complete remission of Cushing's disease.

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.

Aggressive and Metastatic Pituitary Neuroendocrine Tumors: Therapeutic Management and Off-Label Drug Use

Pituitary neuroendocrine tumors (PitNETs) are the most common pituitary tumors and the second most common brain tumors. Although the vast majority (>90%) are benign, a small percentage (<2%) are aggressive. These aggressive PitNETs (AgPitNETs) are defined by the presence of radiological invasion, a high rate of cell proliferation, resistance to conventional treatments, and/or a high propensity for recurrence. Lastly, there are the rare pituitary carcinomas, also known as metastatic PitNETs (MetPitNETs), which account for only 0.2% of cases and are defined by the presence of craniospinal or distant metastases. At present, there are no definitive factors that allow us to predict with certainty the aggressive behavior of PitNETs, making the therapeutic management of AgPitNETs a real challenge. Surgery is considered the first-line treatment for AgPitNETs and MetPitNETs. Radiation therapy can be effective in controlling tumor growth and regulating hormone hypersecretion. Currently, there are no approved non-endocrine medical therapies for the management of AgPitNETs/MetPitNETs, mainly due to the lack of randomized controlled clinical trials. As a result, many of the medical therapies used are off-label drugs, and several are under investigation. Temozolomide (TMZ) is now recognized as the primary medical treatment following the failure of standard therapy (medical treatment, surgery, and radiotherapy) in AgPitNETs/MetPitNETs due to its ability to improve overall and progression-free survival rates in responding patients over 5 years. Other therapeutic options include pituitary-targeted therapies (dopamine agonists and somatostatin analogs), hormonal antisecretory drugs, non-hormonal targeted therapies, radionuclide treatments, and immunotherapy. However, the number of patients who have undergone these treatments is limited, and the results obtained to date have been inconsistent. As a result, it is imperative to expand the cohort of patients undergoing treatment to better determine the therapeutic efficacy and safety of these drugs for individuals with AgPitNETs/MetPitNETs.

Long-term efficacy and safety of subcutaneous pasireotide alone or in combination with cabergoline in Cushing's disease

Objective

This study evaluated short- and long-term efficacy and safety of the second-generation somatostatin receptor ligand pasireotide alone or in combination with dopamine agonist cabergoline in patients with Cushing's disease (CD).

Study design

This is an open-label, multicenter, non-comparative, Phase II study comprising 35-week core phase and an optional extension phase. All patients started with pasireotide, and cabergoline was added if cortisol remained elevated. Eligible patients had active CD, with or without prior surgery, were pasireotide naïve at screening or had discontinued pasireotide for reasons other than safety. Primary endpoint was proportion of patients with a mean urinary free cortisol (mUFC) level not exceeding the upper limit of normal (ULN) at week 35 with missing data imputed using last available post-baseline assessments.

Results

Of 68 patients enrolled, 26 (38.2%) received pasireotide monotherapy and 42 (61.8%) received pasireotide plus cabergoline during the core phase. Thirty-four patients (50.0%; 95% CI 37.6-62.4) achieved the primary endpoint, of whom 17 (50.0%) received pasireotide monotherapy and 17 (50.0%) received combination therapy. Proportion of patients with mUFC control remained stable during the extension phase up to week 99. Treatment with either mono or combination therapy provided sustained improvements in clinical symptoms of hypercortisolism up to week 99. Hyperglycemia and nausea (51.5% each), diarrhea (44.1%) and cholelithiasis (33.8%) were the most frequent adverse events.

Conclusion

Addition of cabergoline in patients with persistently elevated mUFC on maximum tolerated doses of pasireotide is an effective and well-tolerated long-term strategy for enhancing control of hypercortisolism in some CD patients.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT01915303, identifier NCT01915303.

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.

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.

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.

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

CONTEXT

Prospective studies have demonstrated the efficacy of osilodrostat in Cushing's disease. No study has evaluated osilodrostat in a series of patients with paraneoplastic Cushing's syndrome/ectopic ACTH syndrome (PNCS/EAS).

OBJECTIVE

Evaluate in France the real-world efficacy and safety of osilodrostat in PNCS/EAS.

PATIENTS

33 patients with PNCS/EAS with intense/severe hypercortisolism.

METHODS

Retrospective multicenter real-world study. Patients received osilodrostat between May 2019 and March 2022. Median initial dose (range) 4 mg/day (1-60); maximum dose, 20 mg/day (4-100), first, under patient- then cohort- temporary authorizations and after marketing authorization. Regimens used: titration (n = 6), block and replace (n = 16), or titration followed by block and replace (n = 11).

RESULTS

In 11 patients receiving osilodrostat as first-line monotherapy, median 24h- urinary free cortisol (24h-UFC) decreased dramatically (from 26xULN [2.9-659] to 0.11xULN [0.08-14.9]; p < 0.001). In 9 of them, 24h-UFC normalization was achieved in 2 weeks (median). Thirteen additional patients were previously treated with classic steroidogenesis inhibitors but 10/13 were not controlled. In these patients, osilodrostat monotherapy, used in second line, induced a significantly decreased of 24h-UFC (from 2.6xULN [1.1-144] to 0.22xULN [0.12-0.66]; p < 0.01). Nine additional patients received osilodrostat in combination with another anticortisolic drug decreasing 24h-UFC from 11.8xULN (0.3-247) to 0.43xULN (0.33-2.4) (p < 0.01).In parallel, major clinical symptoms/comorbidities improved dramatically with improvement in blood pressure, hyperglycemia and hypokalemia, allowing the discontinuation or dose reduction of their treatments. Adrenal insufficiency (grade 3-4) was reported in 8/33 patients.

CONCLUSIONS

Osilodrostat is a rapidly efficient therapy for PNCS/EAS with severe/intense hypercortisolism. Osilodrostat was generally well tolerated; Adrenal insufficiency was the main side effect.

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.

Innovative tumour targeting therapeutics in Cushing's disease

Cushing's disease (CD) is the most frequent form of endogenous hypercortisolism. Management of this devastating condition relies on pituitary surgery, while effective pharmacological treatment mainly focus on periphery targeting pharmaceuticals. Approved tumour-targeting drugs are limited to dopamine agonists and somatostatin analogues with frequently low efficacy and substantial side effects. Discoveries on the genetics and pathophysiology of corticotroph tumorigenesis brought forward new potential pharmacological targets. Compounds such as retinoic acid although promising in preclinical studies, are not as efficient in the clinic. Others, such as, silibinin, gefitinib and roscovitine are effective in preclinical models, but their efficacy and safety still needs to be determined in patients with CD.

Corticotroph tumor progression speed after adrenalectomy

OBJECTIVES

After bilateral adrenalectomy in Cushing's disease, corticotroph tumor progression occurs in one-third to half of patients. However, progression speed is variable, ranging from slow to rapid. The aim was to explore corticotroph progression speed, its consequences and its risk factors.

DESIGN

A retrospective single-center observational study.

METHODS

In total,103 patients with Cushing's disease who underwent bilateral adrenalectomy between 1990 and 2020 were included. Clinical, biological, histological and MRI features were collected. Median duration of follow-up after bilateral adrenalectomy was 9.31 years.

RESULTS

In total,44 patients progressed (43%). Corticotroph tumor progression speed ranged from 1 to 40.7 mm per year. Progression speed was not different before and after bilateral adrenalectomy (P = 0.29). In univariate analyses, predictive factors for rapid corticotroph tumor progression included the severity of Cushing's disease before adrenalectomy as the cause of adrenalectomy, high ACTH in the year following adrenalectomy and high Ki67 immunopositivity in the tumor. During follow-up, early morning ACTH absolute variation was associated with corticotroph tumor progression speed (P-value = 0.001). ACTH measurement after dynamic testing did not improve this association.

CONCLUSION

After adrenalectomy, corticotroph progression speed is highly variable and manageable with MRI and ACTH surveillance. Progression speed does not seem related to bilateral adrenalectomy but rather to intrinsic properties of highly proliferative and secreting tumors.

Diagnosis and management of hypertension in patients with Cushing's syndrome: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

Endogenous/exogenous Cushing's syndrome is characterized by a cluster of systemic manifestations of hypercortisolism, which cause increased cardiovascular risk. Its biological basis is glucocorticoid excess, acting on various pathogenic processes inducing cardiovascular damage. Hypertension is a common feature in Cushing's syndrome and may persist after normalizing hormone excess and discontinuing steroid therapy. In endogenous Cushing's syndrome, the earlier the diagnosis the sooner management can be employed to offset the deleterious effects of excess cortisol. Such management includes combined treatments directed against the underlying cause and tailored antihypertensive drugs aimed at controlling the consequences of glucocorticoid excess. Experts on endocrine hypertension and members of the Working Group on Endocrine Hypertension of the European Society of Hypertension (ESH) prepared this Consensus document, which summarizes the current knowledge in epidemiology, genetics, diagnosis, and treatment of hypertension in Cushing's syndrome.

Pituitary acting drugs: cabergoline and pasireotide

First-line treatment for Cushing´s disease is transsphenoidal surgery. But in cases of persistent or recurrent disease after surgery, contraindications to surgery, severe hypercortisolism control before surgery, or for patients waiting for radiotherapy effects, medical therapy may be indicated. Pituitary-directed agents include cabergoline and pasireotide. Both drugs present similar potential for biochemical control and pasireotide has additionally been proved to reduce tumor volume. Moreover, pasireotide was evaluated in high quality studies. In respect to safety, both drugs are well tolerated and safe, but special attention should be given for cardiac valve disease and psychiatric disorder for cabergoline, and hyperglycemia for pasireotide.

Aberrant Nuclear Translocation of E2F1 and Its Association in Cushing's Disease

Nonsurgical medical treatments are often performed for Cushing's disease due to high recurrence rates. However, current medical treatment that targets corticotroph adenomas are limited. To develop a treatment that specifically targets corticotrophs in Cushing's disease, it is necessary to identify corticotroph lineage-specific proteins, which are involved in the Cushing's tumor phenotype. We have previously reported that the expression of E2F transcription factor 1 (E2F1), one of the cell cycle regulatory proteins, was increased in corticotrophs in Cushing's disease model mice and was involved in the regulation of POMC gene expression. Phosphorylation of Ser337 of E2F1 (pS337-E2F1) facilitates its binding to the POMC promoter, which was suggested to contribute to elevated POMC expression in corticotrophs. Here, we report that E2F1 expression is specific to the corticotroph lineage in normal human pituitaries and that the E2F1 protein is localized in the cytosol in normal corticotrophs. We show that pS337-E2F1 is localized in the nucleus specifically in Cushing's tumors, while it is localized in the perinuclear cytoplasm in the normal pituitary. This observation demonstrates that pS337 is a marker for Cushing's tumors and suggests that phosphorylation of E2F1 may be a target for developing a novel pharmacological treatment for tumorigenesis and hormone dysregulation of Cushing's disease.

The dopaminergic control of Cushing's syndrome

Cushing's Syndrome (CS), or chronic endogenous hypercortisolism, is a rare and serious disease due to corticotroph pituitary (Cushing's disease, CD) and extra-pituitary (ectopic CS) tumours overproducing ACTH, or cortisol-secreting adrenal tumours or lesions (adrenal CS). The first-line treatment for CS is represented by the surgical removal of the responsible tumour, but surgery might be unfeasible or ineffective and medical treatment can be required in a relevant percentage of patients with CS, especially CD and ectopic CS. Corticotroph pituitary and extra-pituitary tumours, as well as adrenal tumours and lesions responsible for CS express dopamine receptors (DRs), which have been found to mediate inhibition of hormone secretion and/or cell proliferation in experimental setting, suggesting that dopaminergic system, particularly DRs, might represent a target for the treatment of CS. Dopamine agonists (DAs), particularly cabergoline (CAB), are currently used as off-label treatment for CD, the most common form of CS, demonstrating efficacy in controlling hormone secretion and tumour growth in a relevant number of cases, with the improvement of clinical picture, and displaying good safety profile. Therefore, CAB may be considered a reasonable alternative treatment for persistent or recurrent CD after pituitary surgery failure, but occasionally also before pituitary surgery, as adjuvant treatment, or even instead of pituitary surgery as first-line treatment in case of surgery contraindications or refusal. A certain beneficial effect of CAB has been also reported in ectopic CS. However, the role of DAs in the clinical management of the different types of CS requires further evaluations.

MRI-Negative Cushing's Disease: A Review on Therapeutic Management

OBJECTIVES

In this systematic review and meta-analysis, we review the literature regarding patients with Cushing's disease (CD) with negative or inconclusive magnetic resonance imaging (MRI).

METHODS

A quantitative systematic review was performed. Article selection was performed by searching MEDLINE (using PubMed), EMBASE, and Cochrane electronic bibliographic databases.

RESULTS

28 articles described surgical management of inconclusive MRI or MRI-negative CD. A total of 858 patients underwent surgery for their Cushing adenoma. Different types of surgery, including endoscopic endonasal transsphenoidal surgery (EETS) (190 cases) and microscopic endonasal transsphenoidal surgery (METS) (488 cases), were performed on patients with MRI-negative CD. 7 studies, which included 164 patients, did not describe any surgery. EETS and METS are conducted to achieve selective adenomectomy (231 cases), partial adenomectomy (80 cases), total adenomectomy (13 cases), hemihypophysectomy (15 cases), or enlarged adenomectomy (48 cases). Based on available data on these studies, the remission rate, persistence rate, and recurrence rate after different types of surgeries on patients with MRI-negative CD were 72.97%, 27.03%, and 12.05%, respectively. There was no statistically significant difference between EETS and METS in the subanalysis regarding recurrence rate, remission rate, and persistence rate. However, the recurrence rate in the METS group is almost 3 times higher than in the EETS group.

CONCLUSIONS

Surgery has a good prognosis in patients with MRI-negative CD in terms of remission, and EETS has a lower rate of disease recurrence than METS; therefore, EETS seems to be the potential recommended treatment technique, while to confirm the therapeutic method of choice, further investigations should be done.

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.

Individualized medical treatment options in Cushing disease

Cushing disease (CD) is caused by a pituitary tumor which oversecretes adrenocorticotropic hormone (ACTH). It is a serious endocrine disease associated with increased mortality and impaired quality of life. The management of CD remains challenging. Although transsphenoidal surgery is the treatment of choice in most cases, in approximately half of CD patients, second or third-line treatment options are needed. Currently, new medical therapies are available which target adrenal steroidogenesis, pituitary somatostatin and dopamine receptors, and glucocorticoid receptors. Selection of which medication to use should be individualized and is determined by many factors including severity of the disease, possible side effects, patients preferences and local availability. The aim of this article is to describe currently available medical therapy to help clinicians individualize the treatment options in the context of recently updated Pituitary Society recommendations.

Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma: A Systematic Review and Meta-Analysis

INTRODUCTION

Pasireotide (PAS) is a novel somatostatin receptor ligands (SRL), used in controlling hormonal hypersecretion in both acromegaly and Cushing's Disease (CD). In previous studies and meta-analysis, first-generation SRLs were reported to be able to induce significant tumor shrinkage only in somatotroph adenomas. This systematic review and meta-analysis aim to summarize the effect of PAS on the shrinkage of the pituitary adenomas in patients with acromegaly or CD.

MATERIALS AND METHODS

We searched the Medline database for original studies in patients with acromegaly or CD receiving PAS as monotherapy, that assessed the proportion of significant tumor shrinkage in their series. After data extraction and analysis, a random-effect model was used to estimate pooled effects. Quality assessment was performed with a modified Joanna Briggs's Institute tool and the risk of publication bias was addressed through Egger's regression and the three-parameter selection model.

RESULTS

The electronic search identified 179 and 122 articles respectively for acromegaly and CD. After study selection, six studies considering patients with acromegaly and three with CD fulfilled the eligibility criteria. Overall, 37.7% (95%CI: [18.7%; 61.5%]) of acromegalic patients and 41.2% (95%CI: [22.9%; 62.3%]) of CD patients achieved significant tumor shrinkage. We identified high heterogeneity, especially in acromegaly (I² of 90% for acromegaly and 47% for CD), according to the low number of studies included.

DISCUSSION

PAS treatment is effective in reducing tumor size, especially in acromegalic patients. This result strengthens the role of PAS treatment in pituitary adenomas, particularly in those with an invasive behavior, with progressive growth and/or extrasellar extension, with a low likelihood of surgical gross-total removal, or with large postoperative residual tissue.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022328152, identifier CRD42022328152.

Pharmacological management of severe Cushing's syndrome: the role of etomidate

Cushing's syndrome (CS) is an endocrine disease characterized by excessive adrenocortical steroid production. One of the mainstay pharmacological treatments for CS are steroidogenesis enzyme inhibitors, including the antifungal agent ketoconazole along with metyrapone, mitotane, and aminoglutethimide. Recently, osilodrostat was added to this drug class and approved by the US Food and Drug Administration (FDA) for the treatment of Cushing's Disease. Steroidogenesis enzyme inhibitors inhibit various enzymes along the cortisol biosynthetic pathway and may be used preoperatively to lower cortisol levels and reduce surgical risk associated with tumor resection or postoperatively when surgery and/or radiation therapies are not curative. Because their selectivities for steroidogenic enzymes vary, they may even be administered in combination to achieve relatively rapid control of severe hypercortisolemia. Unfortunately, all currently available inhibitors are accompanied by serious adverse side effects that limit dosing and often result in treatment failures. Although more commonly known as a general anesthetic induction agent, etomidate is another member of the steroidogenesis enzyme inhibitor drug class. It suppresses cortisol production primarily by inhibiting 11β-hydroxylase and is the only inhibitor that may be given parenterally. However, the sedative-hypnotic actions of etomidate limit its use as an acute management option for CS. Thus, some have recommended that it be used only in intensive care settings. In this review, we discuss the initial development of etomidate as an anesthetic agent, its subsequent development as a treatment for CS, and the recent advances in dosing and drug development that dissociate sedative-hypnotic and adrenostatic drug actions to facilitate CS treatment in non-critical care settings.

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.

Cushing's disease

Cushing's disease (CD) is the most prevalent cause of endogenous hypercortisolism. CD is responsible for multiple co-morbidities and increased mortality. Accurate and prompt diagnosis and optimal treatment are essential to improve the prognosis of CD. However, the diagnosis of CD is probably one of the most difficult in endocrinology and, therefore, diagnostic workup should be performed in an experienced center. Transsphenoidal surgery performed by an expert surgeon is the only therapeutic option that can offer definitive cure and remains the first-line treatment in most patients. Second-line treatments include pharmacotherapy, pituitary radiotherapy and bilateral adrenalectomy. The second-line therapeutic strategy is complex, must be individualized and performed in a multidisciplinary expert center. Symptomatic treatments of persisting co-morbidities after remission, which are responsible for increased mortality and impaired quality of life is an important part of medical management.

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.

Filamin A is required for somatostatin receptor type 5 expression and pasireotide-mediated signaling in pituitary corticotroph tumor cells

Somatostatin receptor type 5 (SST5) represents the main pharmacological target in the treatment of adrenocorticotroph hormone (ACTH)-secreting tumors. However, molecular predictors of responsiveness to pasireotide require further investigation. The cytoskeleton protein filamin A (FLNA) modulates the responsiveness to somatostatin analogs (SSA) treatment in other types of pituitary tumors by regulating somatostatin receptor type 2 (SST2)/dopamine receptor type 2 (DRD2) expression and activity. Here, we aimed to test the involvement of FLNA in the modulation of SST5 response to SSA in human and murine tumor corticotrophs. Western blot analysis of human corticotropinomas showed that FLNA and SST5 correlate. Both in human primary cultures and AtT-20 cells, FLNA genetic silencing caused a decrease of receptor expression level. Moreover, pasireotide-mediated SST5 downregulation observed in AtT-20 control cells was no further detected in FLNA silenced cells. In AtT-20 cells, in situ PLA experiments revealed an increased number of SST5-FLNA complexes following pasireotide incubation. Finally, FLNA knock down abolished pasireotide-induced SST5 actions on hormone secretion, cell proliferation and apoptosis. In conclusion, FLNA is implicated in SST5 expression modulation and signaling.

Osilodrostat for the treatment of Cushing's disease

INTRODUCTION

The treatment of Cushing's disease (CD) has been advanced well with the introduction of treatment options like transsphenoidal surgery, radiosurgery, bilateral adrenalectomy, and various classes of medication; however, many patients still fail to achieve disease remission. Osilodrostat, an orally bioavailable adrenal steroidogenesis inhibitor, was approved in the USA and EU in 2020 for the treatment of CD.

AREAS COVERED

This review provides an overview of Cushing's disease and the newly FDA approved 11β-hydroxylase inhibitor, osilodrostat, for CD with a focus on pharmacodynamics, pharmacokinetics, safety and efficacy data, and phase 2 and 3 clinical trials.

EXPERT OPINION

Osilodrostat has proven clinical efficacy and tolerability in phase 2 and 3 trials with CD patients who had an inadequate or reoccurring response to transsphenoidal surgery (TSS) and conventional first-line treatment. The phase 3 trial (LINC3) had 86% of the treatment group respond with normal urinary free cortisol (UFC) level compared to 29% in the placebo group (p < 0.001). Deemed as well-tolerated in all current pivotal trials, oral osilodrostat provides a noninvasive option for patients who cannot undergo surgery or patients who have reoccurring hypercortisolemia.

Aggressive Cushing's Disease: Molecular Pathology and Its Therapeutic Approach

Cushing's disease is a syndromic pathological condition caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (ACTHomas) mediated by hypercortisolemia. It may have a severe clinical course, including infection, psychiatric disorders, hypercoagulability, and metabolic abnormalities, despite the generally small, nonaggressive nature of the tumors. Up to 20% of ACTHomas show aggressive behavior, which is related to poor surgical outcomes, postsurgical recurrence, serious clinical course, and high mortality. Although several gene variants have been identified in both germline and somatic changes in Cushing's disease, the pathophysiology of aggressive ACTHomas is poorly understood. In this review, we focused on the aggressiveness of ACTHomas, its pathology, the current status of medical therapy, and future prospects. Crooke's cell adenoma (CCA), Nelson syndrome, and corticotroph pituitary carcinoma are representative refractory pituitary tumors that secrete superphysiological ACTH. Although clinically asymptomatic, silent corticotroph adenoma is an aggressive ACTH-producing pituitary adenoma. In this review, we summarize the current understanding of the pathophysiology of aggressive ACTHomas, including these tumors, from a molecular point of view based on genetic, pathological, and experimental evidence. The treatment of aggressive ACTHomas is clinically challenging and usually resistant to standard treatment, including surgery, radiotherapy, and established medical therapy (e.g., pasireotide and cabergoline). Temozolomide is the most prescribed pharmaceutical treatment for these tumors. Reports have shown that several treatments for patients with refractory ACTHomas include chemotherapy, such as cyclohexyl-chloroethyl-nitrosourea combined with 5-fluorouracil, or targeted therapies against several molecules including vascular endothelial growth factor receptor, cytotoxic T lymphocyte antigen 4, programmed cell death protein 1 (PD-1), and ligand for PD-1. Genetic and experimental evidence indicates that some possible therapeutic candidates are expected, such as epidermal growth factor receptor tyrosine kinase inhibitor, cyclin-dependent kinase inhibitor, and BRAF inhibitor. The development of novel treatment options for aggressive ACTHomas is an emerging task.

Resistance to Dopamine Agonists in Pituitary Tumors: Molecular Mechanisms

Pituitary neuroendocrine tumors (PitNET) are commonly benign tumors accounting for 10-25% of intracranial tumors. Prolactin-secreting adenomas represent the most predominant type of all PitNET and for this subtype of tumors, the medical therapy relies on the use of dopamine agonists (DAs). DAs yield an excellent therapeutic response in reducing tumor size and hormonal secretion targeting the dopamine receptor type 2 (D2DR) whose higher expression in prolactin-secreting adenomas compared to other PitNET is now well established. Moreover, although DAs therapy does not represent the first-line therapy for other PitNET, off-label use of DAs is considered in PitNET expressing D2DR. Nevertheless, DAs primary or secondary resistance, occurring in a subset of patients, may involve several molecular mechanisms, presently not fully elucidated. Dopamine receptors (DRs) expression is a prerequisite for a proper DA function in PitNET and several molecular events may negatively modify DR membrane expression, through the DRs down-regulation and intracellular trafficking, and DR signal transduction pathway. The current mini-review will summarise the presently known molecular events that underpin the unsuccessful therapy with DAs.

The Role of Dopamine Agonists in Pituitary Adenomas

Dopamine agonist therapy is the primary therapy for prolactin-secreting adenomas and usually results in normoprolactinemia, eugonadism, and tumor reduction. Cabergoline is superior to bromocriptine with regard to efficacy and tolerance. Withdrawal of cabergoline can be attempted in patients with normal prolactin levels on low doses of medication and evidence of radiographic tumor involution. Dopamine agonists have been used off label in patients with acromegaly, Cushing disease, and nonfunctioning adenomas. A trial of cabergoline monotherapy can be effective in patients with biochemically mild acromegaly. Cabergoline combination with somatostatin receptor ligands or pegvisomant improves insulin-like growth factor level 1 in majority of patients.

Fatal high-grade skull osteosarcoma 30 years following radiotherapy for Cushing's disease

SUMMARY

Cushing's disease is a rare disorder characterised by excessive cortisol production as a consequence of a corticotroph pituitary tumour. While the primary treatment is surgical resection, post-operative radiation therapy may be used in cases of ongoing inadequate hormonal control or residual or progressive structural disease. Despite improved outcomes, radiotherapy for pituitary tumours is associated with hypopituitarism, visual deficits and, rarely, secondary malignancies. We describe an unusual case of a 67-year-old female with presumed Cushing's disease diagnosed at the age of 37, treated with transsphenoidal resection of a pituitary tumour with post-operative external beam radiotherapy (EBRT), ketoconazole for steroidogenesis inhibition, and finally bilateral adrenalectomy for refractory disease. She presented 30 years after her treatment with a witnessed generalised tonic-clonic seizure. Radiological investigations confirmed an extracranial mass infiltrating through the temporal bone and into brain parenchyma. Due to recurrent generalised seizures, the patient was intubated and commenced on dexamethasone and anti-epileptic therapy. Resection of the tumour revealed a high-grade osteoblastic osteosarcoma. Unfortunately, the patient deteriorated in intensive care and suffered a fatal cardiac arrest following a likely aspiration event. We describe the risk factors, prevalence and treatment of radiation-induced osteosarcoma, an exceedingly rare and late complication of pituitary irradiation. To our knowledge, this is the longest reported latency period between pituitary irradiation and the development of an osteosarcoma of the skull.

LEARNING POINTS

Cushing's disease is treated with transsphenoidal resection as first-line therapy, with radiotherapy used in cases of incomplete resection, disease recurrence or persistent hypercortisolism. The most common long-term adverse outcome of pituitary tumour irradiation is hypopituitarism occurring in 30-60% of patients at 10 years, and less commonly, vision loss and oculomotor nerve palsies, radiation-induced brain tumours and sarcomas. Currently proposed characteristics of radiation-induced osteosarcomas include: the finding of a different histological type to the primary tumour, has developed within or adjacent to the path of the radiation beam, and a latency period of at least 3 years. Treatment of osteosarcoma of the skull include complete surgical excision, followed by systemic chemotherapy and/or radiotherapy. Overall prognosis in radiation-induced sarcoma of bone is poor. Newer techniques such as stereotactic radiosurgery may reduce the incidence of radiation-induced malignancies.

Surgical indications for pituitary tumors during pregnancy: a literature review

PURPOSE

Surgical indications for pituitary tumors during pregnancy are rare, and are derived from a balance between expected benefits, particularly for maternal benefits, and anesthetic/surgical risks.

METHODS

A literature review was performed to define the optimal surgical indications for pituitary adenomas (PA) and other pituitary tumors during pregnancy.

RESULTS

Main benefits are expected in case of critical visual impairment and/or life-threatening endocrine disturbances. Multidisciplinary patient management is systematically required although nonobstetric surgery presents a reasonable risk during pregnancy. The risks of congenital malformation during the first trimester and those of premature birth during the third trimester make the second trimester the optimal period for surgery. In prolactin-secreting, nonsecreting, GH- and TSH-secreting PAs, transsphenoidal surgery (TS) is recommended in cases involving severe visual impairment, characterized by severe visual field deficit, visual acuity impairment, and abnormal optical coherence tomography findings, and when no other medical alternatives are possible and/or sufficient. Uncontrolled and severe Cushing's disease (CD) during pregnancy increases both maternal and fetal morbimortality, thus justifying TS or sometimes dopamine agonist therapy as a safer alternative. Finally, metyrapone, ketoconazole, or bilateral adrenalectomy could be recommended in certain cases after the failure of medical therapies and/or TS. Surgery is also required for suprasellar meningiomas, craniopharyngiomas, and pituitary cysts in the case of severe visual deficit.

CONCLUSION

Surgical indications for pituitary tumors are rare during pregnancy; therefore, surgery should be avoided when possible. Further, the second trimester should be considered as the optimal surgical period. Severe visual disturbance and uncontrolled CD are the main surgical indications during pregnancy.

Cushing's syndrome: Treatment and new therapeutic approaches

Overt Cushing's syndrome is a severe condition responsible for multiple comorbidities and increased mortality. Effective treatment is essential to reduce mortality, improve comorbidities and long-term quality of life. Surgical resection of the causal lesion(s) is generally the first-line and most effective treatment to normalize cortisol secretion. Adjunctive symptomatic treatments of co-morbidities are often necessary both during the active phase of the disease and for persisting co-morbidities after cessation of hypercortisolism. Second-line treatments include various pharmacological treatments, bilateral adrenalectomy, and radiotherapy of corticotroph tumors. The choice of these treatments is complex, must be performed in a multidisciplinary expert team to be individualized for each patient, and use a shared decision-making approach.

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.