Randomized Trial of Osilodrostat for the Treatment of Cushing Disease

Cushing's Syndrome in the Elderly

Management of Cushing's syndrome (CS) can be particularly challenging in older patients, compared with younger individuals, due to the lack of several clinical features associated with cortisol excess along with a greater burden of associated comorbidities. Moreover, the interpretation of diagnostic tests could be influenced by age-related physiological changes in cortisol secretion. While mortality is higher and quality of life is more impaired in the elderly with CS as compared with the younger, there is currently no agreement on the most effective therapeutic options in aged individuals, and safety data concerning medical treatment are scanty. In this review, we summarize the current knowledge about age-related differences in CS etiology, clinical presentation, treatment, and outcomes and describe the potential underlying mechanisms.

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.

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.

How often should we perform magnetic resonance imaging (MRI) for the follow-up of pituitary adenoma?

Magnetic resonance imaging (MRI) is the examination of choice for diagnosing and monitoring pituitary adenoma (also known as pituitary neuroendocrine tumor or PitNET), whether treated or not. However, repeating the examination too often (and sometimes unnecessarily) is costly, and worrying data on tissue accumulation (brain, bone, etc.) of gadolinium atoms dissociated from their carrier molecule (chelator) have led European authorities to ban contrast agents based on linear chelators of gadolinium, which are particularly susceptible to rapid dissociation, in favor of chemically more stable macrocyclic chelators. It is therefore important to determine the optimal frequency for pituitary MRI monitoring in order to safely assess the natural history or therapeutic response of pituitary adenomas. The aim of this article is to summarize the most recent data on optimal follow-up intervals depending on the type, size and location of the pituitary tumor and the clinical situation in general, in order to generate monitoring algorithms to guide clinicians.

Response to Osilodrostat Therapy in Adrenal Cushing's Syndrome

Cushing's disease (CD) is the most common cause of endogenous hypercortisolism. Osilodrostat was demonstrated to be efficient in treating CD, and the mean average dose required for CD control was <11 mg/day. Potential differences in osilodrostat treatment between cortisol-producing adenoma (CPA) and CD have not been reported. The aim of this study was to present two patients with CPA in whom significant differences in the response to therapy compared to CD were found. We demonstrated a case of inverse response of cortisol levels with adrenal tumor progression during the initial dose escalation (Case 1). Simultaneously, severe exaggeration of hypercortisolism symptoms and life-threatening hypokalemia occurred. A further rapid dose increase resulted in the first noticeable cortisol response at a dose of 20 mg/day, and a full response at a dose of 45 mg/day. We also present a case that was initially resistant to therapy (Case 2). The doses required to achieve the first response and the full response were the same as those for Case 1. Our study demonstrated that osilodrostat therapy in patients with CPA may require a different approach than that in CD, with higher doses, faster dose escalation, and a possible initial inverse response or lack of response.

Osilodrostat: A Novel Potent Inhibitor of 11-Beta-Hydroxylase for the Treatment of Cushing's Syndrome

Osilodrostat is a novel potent oral steroidogenesis inhibitor with a non-steroidal chemical structure, recently approved for the treatment of adult patients with endogenous Cushing's syndrome, and Cushing's disease not cured bytab pituitary surgery or in whom pituitary surgery is not an option. Osilodrostat has been evaluated in different multicentre phase II and III clinical studies, and has shown to have notable effects, such as significant reductions in cortisol secretion, associated with significant improvement in body weight, blood pressure, glucose metabolism, lipid profile, psychological status and quality of life. The favourable safety profile, combined with the relevant efficacy, could make osilodrostat suitable as medical treatment in several phases of the Cushing's syndrome treatment journey: before surgery, as preoperative treatment, or instead of surgery, in cases where surgery is not an option or refused, as first-line treatment; after surgery, in cases of persistent or recurrent disease, as second-line treatment; after second surgery or radiotherapy following pituitary surgery as bridging treatment waiting for the definitive disease control, as third-line treatment. Further real-world clinical experience data are needed to confirm the current knowledge.

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.

Aldosterone and aldosterone synthase inhibitors in cardiorenal disease

Modulation of the renin-angiotensin-aldosterone system is a foundation of therapy for cardiovascular and kidney diseases. Excess aldosterone plays an important role in cardiovascular disease, contributing to inflammation, fibrosis, and dysfunction in the heart, kidneys, and vasculature through both genomic and mineralocorticoid receptor (MR)-mediated as well as nongenomic mechanisms. MR antagonists have been a key therapy for attenuating the pathologic effects of aldosterone but are associated with some side effects and may not always adequately attenuate the nongenomic effects of aldosterone. Aldosterone is primarily synthesized by the CYP11B2 aldosterone synthase enzyme, which is very similar in structure to other enzymes involved in steroid biosynthesis including CYP11B1, a key enzyme involved in glucocorticoid production. Lack of specificity for CYP11B2, off-target effects on the hypothalamic-pituitary-adrenal axis, and counterproductive increased levels of bioactive steroid intermediates such as 11-deoxycorticosterone have posed challenges in the development of early aldosterone synthase inhibitors such as osilodrostat. In early-phase clinical trials, newer aldosterone synthase inhibitors demonstrated promise in lowering blood pressure in patients with treatment-resistant and uncontrolled hypertension. It is therefore plausible that these agents offer protection in other disease states including heart failure or chronic kidney disease. Further clinical evaluation will be needed to clarify the role of aldosterone synthase inhibitors, a promising class of agents that represent a potentially major therapeutic advance.

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.

Cushing's Disease: Long-Term Effectiveness and Safety of Osilodrostat in a Polish Group of Patients with Persistent Hypercortisolemia in the Experience of a Single Center

Osilodrostat is a potent oral steroidogenesis inhibitor that has emerged as the new medical agent for patients with Cushing's disease (CD) requiring long-term medical therapy for hypercortisolemia control. Its efficacy and safety have been assessed in clinical trials; however, real-world evidence is still scarce. This study aimed to investigate the long-term treatment (156 weeks) clinical and biochemical effect of osilodrostat in six patients with CD at a single center in Poland, initially participating in the LINC4 study. At week 36, all six patients met the key secondary endpoint of the LINC4 trial, achieving normalization of median urinary free cortisol. Osilodrostat treatment allowed for complete disease control in all patients and none of the patients was excluded due to the lack of treatment effectiveness in 156 weeks of follow-up. All patients demonstrated significant improvement from baseline on most metabolic and cardiovascular parameters, which was most evident at week 36 and sustained throughout the study period. This study supports and strengthens the role of osilodrostat as an effective long-term medical treatment in patients with CD. We also present three patient case histories in detail to highlight the clinical situations that endocrinologists might face during osilodrostat therapy.

Structural and clinical characterization of CYP11B2 inhibition by dexfadrostat phosphate

Aldosterone synthase (CYP11B2) represents a promising drug target because its genetic dysregulation is causally associated with cardiovascular disease, its autonomous activity leads to primary aldosteronism, and its deficiency leads to salt wasting syndromes. The serendipitous discovery that the dextro-rotatory stereoisomer of the racemic aromatase (CYP19A1) inhibitor CGS16949A mediates potent CYP11B2 inhibition led to the purification and clinical development of dexfadrostat phosphate. To characterize the pharmacophore of dexfadrostat phosphate, structure-based enzyme coordination with CYP11B2, CYP11B1 and CYP19A1 was combined with steroid turnover upon in vitro and clinical treatment. Dexfadrostat, but not its 5S-enantiomer (5S-fadrozole), precisely coordinates with the catalytic heme moiety in the space of the CYP11B2 substrate binding pocket forming a tight and stable complex. Conversely, neither rigid nor flexible docking led to a plausible coordination geometry for dexfadrostat in steroid 11β-hydroxylase (CYP11B1 - orthologue to CYP11B2) or in CYP19A1. The inhibitory preference of dexfadrostat was confirmed in vitro using an adrenal cortex-derived cell line. Dexfadrostat phosphate treatment of healthy subjects in the context of a clinical phase 1 study led to a dose-dependent decrease in urinary aldosterone secretion, accompanied by an increase in urinary corticosterone and deoxycorticosterone metabolites. Increased urinary corticosterone metabolites are indicative of CYP11B2 (18-oxidase) inhibition with clinical features reminiscent of patients with inborn corticosterone methyloxidase type II deficiency. An off-target effect on CYP19A1 was not observed as indicated by no clinical changes in testosterone and estradiol levels. Therefore, dexfadrostat exhibits the ideal structural features for binding and catalytic inhibition of CYP11B2 but not CYP11B1. Clinically, treatment with dexfadrostat phosphate leads to suppression of aldosterone levels by inhibiting predominantly one or both final CYP11B2-mediated reactions.

Pharmacological Treatment of Cushing's Syndrome

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

Baxdrostat: A Novel Aldosterone Synthase Inhibitor for Treatment Resistant Hypertension

Hypertension is a global epidemic, affecting around 30.4% of the population and being the leading preventable risk factor for death. Despite the availability of numerous antihypertensive agents, less than 20% of individuals have their blood pressure controlled. Resistant hypertension poses a challenge, but a new class of medication, aldosterone synthase inhibitors (ASI), shows promise. ASI reduces aldosterone production by inhibiting aldosterone synthase. This review article focuses on Baxdrostat, a highly potent ASI currently in phase 3 trials. It discusses the drug's biochemical pathway, efficacy trials in animals and humans, and its potential in uncontrolled hypertension, chronic kidney disease, and primary aldosteronism.

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.

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.

Selectivity of osilodrostat as an inhibitor of human steroidogenic cytochromes P450

Osilodrostat (LCI699) is a potent inhibitor of the human steroidogenic cytochromes P450 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2). LCI699 is FDA-approved for the treatment of Cushing disease, which is characterized by chronic overproduction of cortisol. While phase II and III clinical studies have proven the clinical efficacy and tolerability of LCI699 for treating Cushing disease, few studies have attempted to fully assess the effects of LCI699 on adrenal steroidogenesis. To this end, we first comprehensively analyzed LCI699-mediated inhibition of steroid synthesis in the NCI-H295R human adrenocortical cancer cell line. We then studied LCI699 inhibition using HEK-293 or V79 cells stably expressing individual human steroidogenic P450 enzymes. Our studies using intact cells confirm the potent inhibition of CYP11B1 and CYP11B2 with negligible inhibition of 17-hydroxylase/17,20-lyase (CYP17A1) and 21-hydroxylase (CYP21A2). Furthermore, partial inhibition of the cholesterol side-chain cleavage enzyme (CYP11A1) was observed. To calculate the dissociation constant (Kd) of LCI699 with the adrenal mitochondrial P450 enzymes, we successfully incorporated P450s into lipid nanodiscs and carried out spectrophotometric equilibrium and competition binding assays. Our binding experiments confirm the high affinity of LCI699 to CYP11B1 and CYP11B2 (Kd ≈ 1 nM or less) and much weaker binding for CYP11A1 (Kd = 18.8 μM). Our results confirm the selectivity of LCI699 for CYP11B1 and CYP11B2 and demonstrate partial inhibition of CYP11A1 but not CYP17A1 and CYP21A2.

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

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

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.

[What newly brought endocrinology by the past 2022?]

In the past year, the Federal Project "Fight against Diabetes" 2023-2030 was developed in detail and submitted in detail and submitted to the Government of the Russian Federation, which will significantly improve the practice of working with patients with diabetes, providing them with maximum availability of medical care, including in updated and technologically re -equipped regional endocrinological centers, reviving the active work of "Diabetes schools", "Diabetic foot" rooms, diagnostic laboratories, introducing new forms of communication with patients, including using personal assistants of a doctor, continuous technologies for monitoring glycemia, etc.

Treatment of Cushing Disease With Pituitary-Targeting Seliciclib

CONTEXT

Preclinical studies show seliciclib (R-roscovitine) suppresses neoplastic corticotroph proliferation and pituitary adrenocorticotrophic hormone (ACTH) production.

OBJECTIVE

To evaluate seliciclib as an effective pituitary-targeting treatment for patients with Cushing disease (CD).

METHODS

Two prospective, open-label, phase 2 trials, conducted at a tertiary referral pituitary center, included adult patients with de novo, persistent, or recurrent CD who received oral seliciclib 400 mg twice daily for 4 consecutive days each week for 4 weeks. The primary endpoint in the proof-of-concept single-center study was normalization of 24-hour urinary free cortisol (UFC; ≤ 50 µg/24 hours) at study end; in the pilot multicenter study, primary endpoint was UFC normalization or ≥ 50% reduction in UFC from baseline to study end.

RESULTS

Sixteen patients were consented and 9 were treated. Mean UFC decreased by 42%, from 226.4 ± 140.3 µg/24 hours at baseline to 131.3 ± 114.3 µg/24 hours by study end. Longitudinal model showed significant UFC reductions from baseline to each treatment week. Three patients achieved ≥ 50% UFC reduction (range, 55%-75%), and 2 patients exhibited 48% reduction; none achieved UFC normalization. Plasma ACTH decreased by 19% (P = 0.01) in patients who achieved ≥ 48% UFC reduction. Three patients developed grade ≤ 2 elevated liver enzymes, anemia, and/or elevated creatinine, which resolved with dose interruption/reduction. Two patients developed grade 4 liver-related serious adverse events that resolved within 4 weeks of seliciclib discontinuation.

CONCLUSION

Seliciclib may directly target pituitary corticotrophs in CD and reverse hypercortisolism. Potential liver toxicity of seliciclib resolves with treatment withdrawal. The lowest effective dose requires further determination.

Advances in Molecular Pathophysiology and Targeted Therapy for Cushing's Disease

Cushing's disease is caused by autonomous secretion of adrenocorticotropic hormone (ACTH) from corticotroph pituitary neuroendocrine tumors. As a result, excess cortisol production leads to the overt manifestation of the clinical features of Cushing's syndrome. Severe complications have been reported in patients with Cushing's disease, including hypertension, menstrual disorders, hyperglycemia, osteoporosis, atherosclerosis, infections, and mental disorders. Cushing's disease presents with a variety of clinical features, ranging from overt to subtle. In this review, we explain recent advances in molecular insights and targeted therapy for Cushing's disease. The pathophysiological characteristics of hormone production and pituitary tumor cells are also explained. Therapies to treat the tumor growth in the pituitary gland and the autonomous hypersecretion of ACTH are discussed. Drugs that target corticotroph pituitary neuroendocrine tumors have been effective, including cabergoline, a dopamine receptor type 2 agonist, and pasireotide, a multi-receptor-targeted somatostatin analog. Some of the drugs that target adrenal hormones have shown potential therapeutic benefits. Advances in potential novel therapies for Cushing's disease are also introduced.

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.

Cushing's syndrome: a combined treatment with etomidate and osilodrostat in severe life-threatening hypercortisolemia

Endogenous Cushing's syndrome (CS) is associated with increased morbidity and mortality. Early diagnosis and initiation of therapy are essential, but effective treatment remains a challenge. In a long-term follow-up, biochemical control of hypercortisolemia, especially when severe, is difficult to achieve. Life-threatening hypercortisolemia is difficult to control due to the limitations of pharmacotherapy, including its side effects, and may require etomidate infusion in the intensive care unit (ICU) to rapidly lower cortisol levels. The effectiveness of hypercortisolemia management can be increased by a dual blockade of cortisol production. We report the efficacy, safety, and tolerability of combined therapy with two steroidogenesis inhibitors, etomidate, and osilodrostat, in a 32-year-old woman diagnosed with severe ACTH-dependent hypercortisolemia, subsequently maintaining a stable level of cortisol with osilodrostat monotherapy. This approach enabled achievement of relatively rapid control of the hypercortisolemia while using an etomidate infusion and concomitant increasing doses of oral osilodrostat applying a "titrations strategy." Our experience shows that it is worth taking advantage of the synergistic anticortisolic action of etomidate with osilodrostat.

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.

Treatment of Cushing's syndrome with osilodrostat: practical applications of recent studies with case examples

Endogenous Cushing's syndrome (CS) is a rare endocrine condition frequently caused by a tumor resulting in elevated cortisol levels. Cushing's disease (CD) caused by an adrenocorticotropic hormone-secreting pituitary adenoma is the most common form of endogenous CS. Medical therapy for CD is mostly used as second-line treatment after failed surgery or recurrence and comprises several pituitary-directed drugs, adrenal steroidogenesis inhibitors, and a glucocorticoid receptor blocker, some of which are US Food and Drug Administration (FDA)-approved for this condition. The recent Pituitary Society consensus guidelines for diagnosis and management of CD described osilodrostat, an oral inhibitor of 11β-hydroxylase, as an effective, FDA-approved medical therapy for CD. Because clinical experience outside clinical trials is limited, we provide here a review of published data about osilodrostat and offer example case studies demonstrating practical considerations on the use of this medication. Recommendations regarding osilodrostat are provided for the following situations: specific assessments needed before treatment initiation; monitoring for adrenal insufficiency, hypokalemia, and changes in QTc; the potential value of a slow up-titration in patients with mild disease; managing temporary treatment cessation for patients with CD who have acquired coronavirus disease 2019; monitoring for increased testosterone levels in women; exercising caution with concomitant medication use; considering whether a higher dose at nighttime might be beneficial; and managing cortisol excess in ectopic and adrenal CS. This review highlights key clinical situations that physicians may encounter when using osilodrostat and provides practical recommendations for optimal patient care when treating CS, with a focus on CD.

Long-term efficacy and safety of osilodrostat in Cushing's disease: final results from a Phase II study with an optional extension phase (LINC 2)

BACKGROUND

Many patients with Cushing's disease (CD) require long-term medical therapy to control their hypercortisolism. In the core phase of a Phase II study (LINC 2; NCT01331239), osilodrostat normalized mean urinary free cortisol (mUFC) in 78.9% of patients with CD. Here, we report long-term efficacy and safety data for osilodrostat following completion of an optional extension to LINC 2.

METHODS

Adult patients with CD were enrolled in a 22-week prospective Phase II study. Patients with mUFC ≤ upper limit of normal (ULN) or receiving clinical benefit at week 22 could enter the optional extension. The proportion of complete (mUFC ≤ ULN) or partial (mUFC &gt; ULN but ≥ 50% decrease from baseline) mUFC responders was assessed over time.

RESULTS

Sixteen of 19 enrolled patients entered the extension. Median (range) osilodrostat exposure from baseline to study end was 5.4 years (0.04-6.7); median (range) average dose was 10.6 mg/day (1.1-47.9). Overall response rate (complete and partial mUFC responders) was consistently ≥ 50%. Sustained control of most cardiovascular-related parameters was observed during the extension. The long-term safety profile was consistent with that reported during the core phase. Testosterone levels (females) decreased towards baseline levels during long-term follow-up, with no new or worsening cases of hirsutism during the extension.

CONCLUSIONS

In the longest prospective study of a steroidogenesis inhibitor to date, osilodrostat provided sustained reductions in mUFC for up to 6.7 years of treatment, with no new safety signals emerging during the extension. These findings support osilodrostat as an effective long-term treatment for patients with CD.

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.