Levoketoconazole treatment in endogenous Cushing's syndrome: extended evaluation of clinical, biochemical, and radiologic outcomes

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.

Osilodrostat improves blood pressure and glycemic control in patients with Cushing's disease: a pooled analysis of LINC 3 and LINC 4 studies

PURPOSE

To evaluate the effect of osilodrostat and hypercortisolism control on blood pressure (BP) and glycemic control in patients with Cushing's disease.

METHODS

Pooled analysis of two Phase III osilodrostat studies (LINC 3 and LINC 4), both comprising a 48-week core phase and an optional open-label extension. Changes from baseline in systolic and diastolic BP (SBP and DBP), fasting plasma glucose (FPG), and glycated hemoglobin (HbA1c) were evaluated during osilodrostat treatment in patients with/without hypertension or diabetes at baseline.

RESULTS

Of 210 patients, 82.9% met criteria for hypertension and 40.0% for diabetes at baseline. In patients with hypertension, reductions in mean SBP/DBP were observed from week (W)12 to W72, and 49.1%/58.5% of patients with high SBP/DBP (> 130/>90 mmHg) at baseline had normotensive levels at W72. Antihypertensive medication dose was reduced/stopped in 26.8% of patients, and the proportion taking antihypertensive medication decreased from 54.3% at baseline to 47.3% at W72. In patients with diabetes, mean FPG and HbA1c decreased from W12 to W72, and 33.3%/61.5% with high FPG/HbA1c (≥ 100 mg/dL/≥6.5%) at baseline had normal levels at W72. Antihyperglycemic medication dose was reduced/stopped in 35.7% of patients, and the proportion taking antihyperglycemic medication decreased from 21.9% at baseline to 17.1% at W72; improvements in SBP/DBP and FPG/HbA1c were correlated with improvement in mean urinary free cortisol but not weight change. BP/glycemic parameters generally remained normal in patients without hypertension/diabetes at baseline.

CONCLUSIONS

Patients with Cushing's disease and comorbid hypertension/diabetes receiving osilodrostat had rapid and sustained improvements in SBP/DBP and glycemic control, respectively.

Osilodrostat treatment in patients with Cushing's disease of Asian or non-Asian origin: a pooled analysis of two Phase III randomized trials (LINC 3 and LINC 4)

Cushing's disease is associated with increased morbidity and mortality. Osilodrostat, a potent oral 11β-hydroxylase inhibitor, provided rapid, sustained mean urinary free cortisol (mUFC) normalization in Cushing's disease patients in two Phase III studies (LINC 3, NCT02180217; LINC 4, NCT02697734). Here, we evaluate the efficacy and safety of osilodrostat in Cushing's disease in patients of Asian origin compared with patients of non-Asian origin. Pooled data from LINC 3 and LINC 4 were analyzed. Outcomes were evaluated separately for Asian and non-Asian patients. For the analysis, 210 patients were included; 56 (27%) were of Asian origin. Median (minimum-maximum) osilodrostat dose was 3.8 (1-25) and 7.3 (1-47) mg/day in Asian and non-Asian patients, respectively. mUFC control was achieved at weeks 48 and 72 in 64.3% and 68.1% of Asian and 68.2% and 75.8% of non-Asian patients. Improvements in cardiovascular and metabolic-related parameters, physical manifestations of hypercortisolism, and quality of life were similar in both groups. Most common adverse events (AEs) were adrenal insufficiency (44.6%) in Asian and nausea (45.5%) in non-Asian patients. AEs related to hypocortisolism and pituitary tumor enlargement occurred in more Asian (58.9% and 21.4%) than non-Asian patients (40.3% and 9.1%). Of Asian and non-Asian patients, 23.2% and 13.6%, respectively, discontinued because of AEs. Asian patients with Cushing's disease generally required numerically lower osilodrostat doses than non-Asian patients to achieve beneficial effects. Hypocortisolism-related AEs were reported in more Asian than non-Asian patients. Together, these findings suggest that Asian patients are more sensitive to osilodrostat than non-Asian patients.

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).

New Trends in Treating Cushing's Disease

Rates of recurrence and/or persistence of Cushing's disease after surgical treatment are high. Recently, advances in molecular insights and a better understanding of pathophysiology have enabled the development of potential therapeutic targets that could control adrenocorticotropic hormone (ACTH) and cortisol secretion or even reduce tumour cell proliferation. At the pituitary level, pasireotide is an approved somatostatin receptor ligand, and compounds targeting cell cycle regulation, cell signalling and epigenetics are now under investigation. Levoketoconazole and osilodrostat are novel steroid inhibitors, and relacorilant overcomes the adverse effects of mifepristone. Adrenal ACTH receptor blockage and immunotherapy could also play a role.

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.

Efficacy and Safety of Levoketoconazole in Managing Cushing's Syndrome: A Systematic Review

No systematic review has holistically analysed the efficacy and safety of levoketoconazole, a novel purified 2S,4R enantiomer of ketoconazole, believed to be 15- to 25-fold more potent than ketoconazole for managing Cushing's syndrome (CS). We undertook this meta-analysis to address this knowledge gap. Electronic databases were searched for studies involving patients with CS receiving levoketoconazole in the intervention arm. The primary outcome was to evaluate changes in mean 24-hour urine-free cortisol (mUFC) levels. Secondary outcomes were to evaluate alterations in cortisol and adverse events. SONICS study showed that normalisation of mUFC was seen in 61%, 55%, and 41% of the patients at the end of 6, 9, and 12 months therapy, respectively. The LOGICs study showed that withdrawal of levoketoconazole was associated with a significant increase in mUFC from 81.3 ± 35.7 to 220.8 ± 333.5 nmol/24h. The late-night salivary-cortisol (LNSC) increase during the drug withdrawal phase was 2.6 nmol/L in the placebo group (PG) compared to 2.2 nmol/L in the levoketoconazole group (LG) (P < 0.05). Re-initiation of levoketoconazole in original LG was associated with a decrease in mUFC from 224.3 ± 341.3 to 135.6 ± 87.3 nmol/24h. Initiation of levoketoconazole in the original PG was associated with a decrease in mUFC from 537.9 ± 346.0 to 141.3 ± 130.3 nmol/24h. Normalisation of mUFC was observed in 50.0% patients in LG compared to 4.5% in the placebo group. The median time for the response was 25 days. The median time to loss of therapeutic response was significantly shorter for PG (24 days) compared to LG (62 days) (P < 0.0001). Levoketoconazole has good efficacy and safety in CS. Bigger and longer studies are warranted to establish its superiority over ketoconazole.

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.

A clinical perspective on ectopic Cushing's syndrome

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

Iatrogenic adrenal insufficiency in adults

Iatrogenic adrenal insufficiency (IAI) is the most common form of adrenal insufficiency in adult patients, although its overall exact prevalence remains unclear. IAI is associated with adverse clinical outcomes, including adrenal crisis, impaired quality of life and increased mortality; therefore, it is imperative that clinicians maintain a high index of suspicion in patients at risk of IAI to facilitate timely diagnosis and appropriate management. Herein, we review the major causes, clinical consequences, diagnosis and care of patients with IAI. The management of IAI, particularly glucocorticoid-induced (or tertiary) adrenal insufficiency, can be particularly challenging, and the provision of adequate glucocorticoid replacement must be balanced against minimizing the cardiometabolic effects of excess glucocorticoid exposure and optimizing recovery of the hypothalamic-pituitary-adrenal axis. We review current treatment strategies and their limitations and discuss developments in optimizing treatment of IAI. This comprehensive Review aims to aid clinicians in identifying who is at risk of IAI, how to approach screening of at-risk populations and how to treat patients with IAI, with a focus on emergency management and prevention of an adrenal crisis.

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.

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.

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.

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.

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.