Ketoconazole in Cushing's disease: is it worth a try?

Drug-induced endocrine blood pressure elevation

Patients with uncontrolled hypertension are at risk for cardiovascular complications. The majority of them suffers from unidentified forms of hypertension and a fraction has so-called secondary hypertension with an identifiable cause. The patient's medications, its use of certain herbal supplements and over-the-counter agents represent potential causal factors for secondary hypertension that are often overlooked. The current review focuses on drugs that are likely to elevate blood pressure by affecting the human endocrine system at the level of steroid synthesis or metabolism, mineralocorticoid receptor activity, or by affecting the catecholaminergic system. Drugs with known adverse effects but where benefits outweigh their risks, drug candidates and market withdrawals are reviewed. Finally, potential therapeutic strategies are discussed.

Surgical Outcomes and Comorbidities in Cushing Disease: 30 Years of Experience in a Referral Center

OBJECTIVE

Cushing disease (CD) is a rare, poorly understood entity. Our aim was to add our clinical experience of >30 years in a multidisciplinary specialized unit to the global knowledge of CD.

METHODS

This descriptive retrospective study included all patients admitted to the Endocrinology and Nutrition Department of the Virgen del Rocío University Hospital, Seville, Spain, from January 1980 to May 2016. All patients had a definitive diagnosis of CD.

RESULTS

Total sample included 119 patients; 100 (84%) were female. Median age at diagnosis was 37.97 years (interquartile range [IQR]: 25.89-45.07 years). Median follow-up was 88 months (IQR: 45.50-157.00 months). Most tumors were microadenomas (62/95) (5.1 mm [IQR: 4.0-7.0 mm]) without sinus invasion. Surgical procedures were conventional transsphenoidal surgery (CTSS) (101/108; cured 70 after first attempt) and expanded endoscopic transsphenoidal surgery (EETSS) (7/108; cured 5 after first attempt); 11 patients did not receive surgical treatment. Fourteen patients received radiotherapy after a first surgery and 5 patients after a second surgical removal attempt. In 13 patients (12.04%), CD relapse was demonstrated after initial CTSS (median disease-free period 65 months [IQR: 45-120 months]). Ten patients developed panhypopituitarism owing to the surgical procedure (CTSS); 8 patients developed panhypopituitarism after adjuvant radiotherapy.

CONCLUSIONS

We observed slightly inferior cure rate after first surgery compared with moderately better relapse rates and time to relapse. Radiotherapy after surgery failure seemed to be more effective than CTSS; however, EETSS may be a valid alternative. Postoperative panhypopituitarism rate after first surgery was lower than expected; after radiotherapy, our results were comparable to other series.

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

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

Why we should still treat by neurosurgery patients with Cushing's disease and a normal or inconclusive pituitary MRI

CONTEXT

In patients with Cushing's disease (CD) and a typical image of adenoma at MRI, transsphenoidal surgery is consensual. However, when MRI is inconclusive or normal, some authors now advocate medical treatment instead. The implicit assumption is that modern MRI should miss only very small microadenomas, too difficult to visualize at surgery.

OBJECTIVE

To analyze the evolution with time of the performances of MRI and the outcomes of surgery in CD patients with a typical image of adenoma vs. inconclusive or normal MRI.

METHODS AND PATIENTS

Retrospective single center study of 195 CD patients treated by transsphenoidal surgery between 1992 and 2018, using first a translabial microscopic and then a transnasal endoscopic approach. Patients with inconclusive or normal MRI were explored by bilateral inferior petrosal sinus sampling (BIPSS). Four MRI groups were defined : microadenomas (n=89), macroadenomas (n=18), or MRI either inconclusive (n=44) or normal (n=44).

RESULTS

The proportion of inconclusive/normal MRI decreased with time, from 60% (21/35) in 1992-96 to 27% (14/51) in 2012-2018 (p=0.037).In the 4 MRI groups, per-operatory adenoma visualization rate was only slightly lower when MRI was normal (95%; 100%; 86%; 79% ; p=0.012) and postoperative remission rates were not different (85%; 94%; 73%; 75 %; p= 0.11).

CONCLUSION

The diagnostic performances of MRI have improved but remain inferior to the eye of an expert neurosurgeon, best assisted by endoscopy. We propose that patients with CD and an inconclusive/normal MRI be still addressed to an expert neurosurgeon for transsphenoidal surgery rather than treated medically.

Radiotherapy as a tool for the treatment of Cushing's disease

Treatment of Cushing's disease (CD) is one of the most challenging tasks in endocrinology. The first-line treatment, transsphenoidal pituitary surgery, is associated with a high failure rate and a high prevalence of recurrence. Re-operation is associated with an even higher rate of a failure and recurrence. There are three main second-line treatments for CD - pituitary radiation therapy (RT), bilateral adrenalectomy and chronic cortisol-lowering medical treatment. All these treatments have their limitations. While bilateral adrenalectomy provides permanent cure of the hypercortisolism in all patients, the unavoidable chronic adrenal insufficiency and the risk of development of Nelson syndrome are of concern. Chronic cortisol-lowering medical treatment is not efficient in all patients and side effects are often a limiting factor. RT is efficient for approximately two-thirds of all patients with CD. However, the high prevalence of pituitary insufficiency is of concern as well as potential optic nerve damage, development of cerebrovascular disease and secondary brain tumours. Thus, when it comes to decide appropriate treatment for patients with CD, who have either failed to achieve remission with pituitary surgery, or patients with recurrence, the pros and cons of all second-line treatment options must be considered.

Functioning Pituitary Adenomas - Current Treatment Options and Emerging Medical Therapies

Pituitary adenomas are benign tumours comprising approximately 16% of all primary cranial neoplasms. Functioning pituitary adenomas (prolactinomas, somatotroph, corticotroph, thyrotroph and rarely gonadotroph adenomas) cause complex clinical syndromes and require prompt treatment to reduce associated morbidity and mortality. Treatment approaches include transsphenoidal surgery, medical therapy and radiation. Medical therapy is the primary therapy for prolactinomas, and surgery by a skilled neurosurgeon is the first-line approach for other functioning pituitary adenomas. A multimodal treatment is frequently necessary to achieve biochemical and clinical control, especially, when surgery is not curative or when medical therapy fails. Several emerging, novel, medical treatments for acromegaly, Cushing's disease and prolactinomas are in phase II and III clinical trials and may become effective additions to the current drug armamentarium. The availability of various management options will allow an individualised treatment approach based on the unique tumour type, clinical situation and patient preference.

Therapeutic options after surgical failure in Cushing's disease: A critical review

Cushing's disease (CD) is the most common etiology of Cushing's syndrome (CD) due to corticotroph pituitary adenoma, which are in most cases small (80-90% microadenomas) and in about 40% cannot be visualized on imaging of the sella. First-line treatment for CD is transsphenoidal surgery (TSS) with the aim of complete adenoma removal and preservation of pituitary gland function. As complete adenoma resection is not always possible, surgical failure is a common problem. This can be the case either due to persistent hypercortisolism after first TSS or recurrence of hypercortisolism after initially achieving remission. For these scenarios exist several therapeutic options with their inherent characteristics, which will be covered by this review.

Advances in the medical treatment of Cushing's syndrome

Cushing's syndrome is associated with multisystem morbidity and, when suboptimally treated, increased mortality. Medical therapy is an option for patients if surgery is not successful and can be classified into pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. In the last decade there have been new developments in each drug category. Targeting dopamine and somatostatin receptors on corticotroph adenomas with cabergoline or pasireotide, or both, controls cortisol production in up to 40% of patients. Potential new targets in corticotroph adenomas include the epidermal growth factor receptor, cyclin-dependent kinases, and heat shock protein 90. Osilodrostat and levoketoconazole are new inhibitors of steroidogenesis and are currently being evaluated in multicentre trials. CORT125134 is a new selective glucocorticoid receptor antagonist under investigation. We summarise the drug therapies for various forms of Cushing's syndrome and focus on emerging drugs and drug targets that have the potential for new and effective tailor-made pharmacotherapy for patients with Cushing's syndrome.

TREATMENT OF CUSHING'S SYNDROME : WHAT PLACE FOR MEDICAL TREATMENT?

Surgery plays a major role as a first-line treatment of the different etiologies of Cushing's syndrome (CS) and bilateral adrenalectomy (BA) is extremely effective as a second line, so that there seems to be little room for medical treatment (MT). However, during the past years several drugs acting either on ACTH secretion or cortisol synthesis have been developed, so that MT of CS might be reassessed. After briefly analyzing the efficiency and tolerance of surgical and medical treatments of CS we try to distinguish consensual and controversial indications for MT. We believe the former include "pre-operative treatment" in rare patients in whom the severity of CS is likely to increase the risks of surgery; "inoperability" for rare patients who cannot be operated even when CS is controlled and "surgical failure or recurrence", mainly in patients Cushing's disease (CD) not in remission after TSS. Controversial indications include "unavailability of an expert surgeon", which we believe does not make sense when the cost of MT is taken into consideration. Finally in patients with the "surgical failure or recurrence" indication the balance between efficacy and side effects of MT should be balanced with the efficacy and side effects of BA.

Low-dose etomidate for the management of severe hypercortisolaemia in different clinical scenarios: a case series and review of the literature

BACKGROUND

Severe Cushing's syndrome (SCS) is associated with acute cardiovascular, metabolic and infectious complications. It is considered an emergency, requiring an immediate diagnosis, together with a broad spectrum of supportive and hypocortisolaemic treatments. Surgical intervention, aimed at removing the source of cortisol or adrenocorticotropic hormone (ACTH), is the optimal treatment in most cases of Cushing's syndrome. However, in hypercortisolaemic states, surgical intervention has high rates of perioperative mortality and morbidity. Oral adrenal steroidogenesis inhibitors, even if more effective in combination, are not always efficient enough or well tolerated. Despite their common use, a more potent, parental, immediate, and thus life-saving, therapy is necessary.

METHODS

The authors present three different clinical scenarios of etomidate treatment in patients hospitalized in the third reference endocrinological centre in Poland between 2016 and 2017.

RESULTS

Patients with Cushing's disease, ectopic Cushing's syndrome and adrenocortical carcinoma presented with severe hypercortisolaemia and exacerbated cortisol-dependent comorbidities. In these three cases, etomidate acted as an accurate, well tolerated and effective cortisol-lowering drug for several days or even months. Patients were monitored in a general ward setting, and no side effects of the therapy were observed.

CONCLUSIONS

In doses far lower than those used for anaesthesia, etomidate works as a useful cortisol-lowering therapy in patients intolerant to or unable to take oral medications. Additionally, if urgent, the most potent and effective medical intervention is necessary, and clinicians should be aware of such a therapeutic option.

The Treatment of Refractory Pituitary Adenomas

Refractory pituitary adenomas (PAs) are defined as aggressive-invasive PAs characterized by a high Ki-67 index, rapid growth, frequent recurrence, and resistance to conventional treatments. It is notoriously difficult to manage refractory PAs because the efficacy of current therapeutic options is limited. The purpose of this review is to address currently employed and promising therapeutic strategies for the treatment of refractory PAs. Except for prolactinomas, neurosurgery is the first-line option, but most refractory PAs often recur or re-grow after initial surgery and require further treatments. Medical therapy, radiotherapy and re-operation are explored when surgery has failed to completely resect tumors; however, refractory PAs are usually resistant to these treatments. As a salvage treatment, temozolomide (TMZ) has shown promising results and is currently used for all types of refractory PAs. However, not all refractory PAs are responsive to TMZ treatment, and some of these PAs are resistant to TMZ. Although targeted therapies such as vascular endothelial growth factor, epidermal growth factor and mTOR inhibitors have also been used to treat refractory PAs, the effectiveness of these targeted therapies is still not known due to a lack of data from randomized prospective trials. As a novel therapeutic method, cancer immunotherapy is a promising strategy for the treatment of refractory PAs, but further preclinical research and clinical trials are needed to assess the efficacy of this new approach. In summary, early identification and a multidisciplinary approach are required to treat refractory PAs.

Safety and Efficacy of Subcutaneous Pasireotide in Patients With Cushing's Disease: Results From an Open-Label, Multicenter, Single-Arm, Multinational, Expanded-Access Study

Introduction: The efficacy and safety of subcutaneous (sc) pasireotide have been evaluated in a Phase III trial. Here, we report safety and efficacy results from a multinational, expanded-access study of pasireotide sc in patients with Cushing's disease (CD) in a real-world setting (clinicaltrials.gov, identifier: NCT01582061). Methods: Adults with active CD previously untreated with pasireotide were enrolled; pasireotide sc was initiated at 600 μg twice daily (bid; EU countries) or 900 μg bid (non-EU countries; 600 μg bid in patients with impaired glucose metabolism). Pasireotide dose could be adjusted in 300 μg increments/decrements to a maximum of 900 μg bid or minimum of 300 μg bid for sustained urinary free cortisol (UFC) normalization/tolerability issues. Primary objective: document the safety of pasireotide sc in patients with CD. Key secondary objectives: assess the proportion of patients with mean UFC (mUFC) not exceeding the upper limit of normal (ULN) and changes from baseline in clinical signs/symptoms and quality of life (QoL) to weeks 12, 24, and 48. Results: One hundred and four patients received pasireotide: female, n = 84 (80.8%); median duration of pasireotide exposure, 25.1 weeks; median (range) baseline mUFC, 321.2 nmol/24 h (142-10,920; 2.3 × ULN [1.0-79.2]). Forty (38.5%) patients completed the study. The most common reasons for premature discontinuation of pasireotide were unsatisfactory therapeutic effect (n = 26, 25.0%) and adverse events (AEs; n = 20, 19.2%). Drug-related grade 3/4 AEs or drug-related serious AEs (primary endpoint) were documented in 42 (40.4%) patients, most commonly diabetes mellitus (n = 12, 11.5%) and hyperglycemia (n = 8, 7.7%). All patients experienced ≥1 AE and most (n = 102; 98.1%) reported ≥1 drug-related AE; six (5.8%) patients discontinued treatment because of hyperglycemia-related AEs. At weeks 12, 24, and 48, respectively, 36/66 (54.5%), 22/46 (47.8%), and 9/21 (42.9%) evaluable patients had normalized mUFC levels. Clinical signs/symptoms and QoL were also improved. Conclusions: In an international, real-world, clinical-practice setting, pasireotide sc was generally well-tolerated (no new safety signals were identified), effectively reduced UFC (normalization in ~50% of evaluable patients) and improved clinical signs and QoL in patients with CD. While hyperglycemia-related AEs were common, consistent with previous studies, most were manageable, with <6% of patients discontinuing treatment because of these events.

Effect of cabergoline monotherapy in Cushing's disease: an individual participant data meta-analysis

CONTEXT

The primary treatment of choice for Cushing's disease (CD) is the removal of the pituitary adenoma by transsphenoidal surgery (TSS). The surgical failure is seen in up to 75% of cases depending on the experience of the surgeon in different studies. Medical therapy is one of the options for the treatment of recurrent or persistent CD.

METHODOLOGY

The primary outcome of this meta-analysis was to find the proportion of patients achieving normalisation of 24-h urinary free cortisol (remission of CD) following cabergoline monotherapy. Literature search was conducted in January 2018 in PubMed/MEDLINE database from its date of inception to 31st December 2017. The search strategy used was "[(cushing) OR Cushing's] AND cabergoline". Individual participant data were extracted from the included studies and risk of bias was analysed by review checklist proposed by MOOSE.

RESULTS

The individual participant data of 124 patients from six observational studies were included in this meta-analysis. 92 patients (74.2%) had past pituitary surgery. The proportion of patients achieving remission of Cushing’s disease (CD) with cabergoline monotherapy was 34% (95% confidence interval 0.26–0.43; P = 0.001) [corrected]. The previous surgery [odds ratio (OR) 28.4], duration of cabergoline monotherapy (OR 1.31) and maximum cabergoline dose (OR 0.19) were predictors for remission of CD. Mild and severe side effects were reported in 37.3% and 5.6% of patients, respectively, during cabergoline monotherapy.

CONCLUSIONS

This meta-analysis shows that cabergoline monotherapy is a reasonable alternative for subjects with persistent or recurrent CD after TSS. It can also be used in CD patients either as a bridge therapy while waiting for surgery or in those unwilling for surgery or have contraindication to it.

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

INTRODUCTION AND AIM

Medical treatment is increasingly used in patients with Cushing's syndrome (CS). Metyrapone (MET) is an inhibitor of 11β-hydroxylase: retrospective studies reported a decrease of cortisol secretion in 50% of cases. We evaluated the effectiveness of MET in an observational study, considering the normalization of urinary-free cortisol (UFC) and late-night salivary cortisol (LNSC) levels.

MATERIALS AND METHODS

We enrolled 31 patients with CS, treated with MET for at least 1 month (16 for primary treatment and 15 after surgical failure). A planned dose-titration regimen considering baseline UFC levels was adopted; MET dose was uptitrated until UFC normalization, surgery, or side effect occurrence. UFC and LNSC levels were routinely measured by liquid chromatography-tandem mass spectrometry.

RESULTS

Patients were treated with a median dose of 1000 mg for 9 months. UFC and LNSC decreased quickly after the first month of treatment (-67 and -57% from baseline), with sustained UFC normalization up to 12 and 24 months (in 13 and 6 patients, respectively). UFC and LNSC normalized later (after 3-6 months) in patients with severe hypercortisolism (>5-fold baseline UFC). Regarding the last visit, 70 and 37% of patients normalized UFC and LNSC, respectively. Body weight reduction (-4 kg) was observed after UFC normalization. Severe side effects were not reported, half of the female patients complained of hirsutism, and blood pressure was not increased.

CONCLUSIONS

MET therapy is a rapid-onset, long-term effective, and safe medical treatment in CS patients, achieving UFC normalization (in 70% of patients) more than cortisol rhythm recovery (in 37% of subjects).

Effectiveness of medical treatment for Cushing's syndrome: a systematic review and meta-analysis

PURPOSE

To systematically review the effectiveness of medical treatment for Cushing's syndrome in clinical practice, regarding cortisol secretion, clinical symptom improvement, and quality of life. To assess the occurrence of side effects of these medical therapies.

METHODS

Eight electronic databases were searched in March 2017 to identify potentially relevant articles. Randomized controlled trials and cohort studies assessing the effectiveness of medical treatment in patients with Cushing's syndrome, were eligible. Pooled proportions were reported including 95% confidence intervals.

RESULTS

We included 35 articles with in total 1520 patients in this meta-analysis. Most included patients had Cushing's disease. Pooled reported percentage of patients with normalization of cortisol ranged from 35.7% for cabergoline to 81.8% for mitotane in Cushing's disease. Patients using medication monotherapy showed a lower percentage of cortisol normalization compared to use of multiple medical agents (49.4 vs. 65.7%); this was even higher for patients with concurrent or previous radiotherapy (83.6%). Mild side effects were reported in 39.9%, and severe side effects were seen in 15.2% of patients after medical treatment. No meta-analyses were performed for clinical symptom improvement or quality of life due to lack of sufficient data.

CONCLUSIONS

This meta-analysis shows that medication induces cortisol normalization effectively in a large percentage of patients. Medical treatment for Cushing's disease patients is thus a reasonable option in case of a contraindication for surgery, a recurrence, or in patients choosing not to have surgery. When experiencing side effects or no treatment effect, an alternate medical therapy or combination therapy can be considered.

Should we avoid using ketoconazole in patients with severe Cushing’s syndrome and increased levels of liver enzymes?

We read with interest the paper of Young et al. in which the authors recommend avoiding ketoconazole in the treatment of Cushing’s syndrome when patients display increased liver enzymes (>2-fold the upper limit of normal (ULN)). We found in a small series of patients that We read with interest the paper of Young et al. in which the authors recommend avoiding ketoconazole in the treatment of Cushing’s syndrome when patients display increased liver enzymes (>2-fold the upper limit of normal (ULN)). Although limited, our experience suggests that liver function tests may improve during ketoconazole treatment and that, in a life-threatening situation such as severe Cushing’s syndrome, increased liver enzymes should not preclude ketoconazole prescription.

Paraneoplastic Cushing syndrome, case-series and review of the literature

OBJECTIVES

Paraneoplastic Cushing syndrome is a rare condition, representing a small fraction of the adrenocorticotropic hormone (ACTH)-dependent cases of Cushing syndrome Methods: Four case descriptions and literature review, highlighting the diagnostic challenges and treatment options are presented.

RESULTS

Different tumor types can be associated with ectopic ACTH secretion. The most common types are bronchial carcinoids and small cell lung carcinoma (SCLC). However, in approximately 10 to 20% of the cases, no overt tumor (occult tumor) can be found. The diagnosis is made in a multistep process. Firstly, hypercortisolemia and adrenocorticotropin hormone dependency have to be confirmed. Distinction between a pituitary or ectopic cause can be cumbersome. MRI of the pituitary gland, a corticotropin releasing hormone stimulation test and a sinus petrosus sampling can be used. Treatment options consist of tumor management, somatostatin analogs, steroidogenesis inhibitors, and bilateral adrenalectomy.

CONCLUSION

Clinicians should consider the diagnosis, and opt for specific treatment, especially in patients with a history of neuroendocrine tumors.

Wahab N, Mustafa N, Sukor N, Kamaruddin NA. Fluconazole as a Safe and Effective Alternative to Ketoconazole in Controlling Hypercortisolism of Recurrent Cushing's Disease: A Case Report

INTRODUCTION

Ketoconazole has long been the first-line medical therapy for controlling hypercortisolism secondary to either pituitary or adrenal pathology. However, it is largely unavailable in most countries. As a result, we have turned to fluconazole as a viable alternative in view of its favourable safety profile.

CASE PRESENTATION

A 50-year-old lady developed recurrent Cushing's disease after being in remission following transsphenoidal surgery (TSS) for a left pituitary microadenoma 16 years ago. The repeat MRI showed a right pituitary microadenoma (1.7 mm × 1.3 mm) for which she underwent a second TSS. However, she continued to have persistent hypercortisolism despite repeated MRIs showing absence of tumour recurrence. She refused bilateral adrenalectomy and external radiotherapy. Ketoconazole was commenced at 200 mg twice daily for disease control but this was hindered by intolerable side effects including pruritus and skin exfoliation. In the meantime, she suffered a right hypertensive basal ganglia hemorrhage. Treatment was subsequently switched to cabergoline and the dose titrated to 0.5 mg daily. Fluconazole 400 mg daily was later added to control the persistent disease. Her clinical and biochemical parameters improved markedly three months after the addition of fluconazole. No adverse event was reported. Her disease has remained stable for the last 15 months up until the time of the recent clinic review.

CONCLUSIONS

This case demonstrates the long-term efficacy of fluconazole in tandem with cabergoline for the control of recurrent Cushing's disease.

Cushing's Syndrome in Pediatrics: An Update

Cushing syndrome (CS) is a multisystem disorder resulting from the prolonged exposure to excess glucocorticoids. In children, CS most commonly results from the exogenous administration of steroids and the typical presentation is height deceleration concomitant with weight gain. Endogenous and ectopic causes are rare. CS in children may be associated with distinct germline and somatic mutations. Clinical practice guidelines are available assist clinicians. Patients should be referred to multidisciplinary centers of excellence with experience in endocrinology and surgery. Early detection and treatment is essential to reduce associated acute and long-term morbidity and potential death.

Medical Therapy for Cushing's Syndrome in the Twenty-first Century

Medical therapy has a useful adjunctive role in many patients with Cushing's syndrome. Patients with pituitary corticotroph adenomas who have received radiation therapy to the sella require medical therapy until the effects of radiation therapy occur. In addition, patients with Cushing's syndrome who cannot undergo surgery promptly, including those who are acutely ill and cannot safely undergo tumor resection, may benefit from medical therapy as a bridge to surgery. Other possible candidates for medical therapy are those with unresectable tumors or those whose tumor location remains unknown despite adequate diagnostic evaluation.

Hepatic safety of ketoconazole in Cushing's syndrome: results of a Compassionate Use Programme in France

OBJECTIVE

Ketoconazole (KTZ) is one of few available treatments for Cushing's syndrome (CS). Although KTZ has been associated with severe hepatotoxicity, little information is available about hepatic safety in CS. The aim of this study was to document changes in liver function in patients with CS treated with KTZ.

DESIGN

An observational prospective French cohort study (Compassionate Use Programme (CUP)).

METHODS

Enrolled patients were stratified into a KTZ-naive cohort and a cohort already treated by another formulation of ketoconazole (KTZ-switch cohort). Liver function markers (alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, γ-glutamyltransferase and bilirubin) were monitored at regular intervals. Patients with ALT > 3 × ULN (upper limit of normal), total bilirubin > 2 × ULN or both ALP > 2 × ULN and ALT > ULN were considered to have liver injury.

RESULTS

Overall, 108 patients were analysed (47 KTZ-naïve; 61 KTZ-switch). The median KTZ dose was 600 mg/day. Most abnormalities observed were asymptomatic mild increases of liver enzymes. Four patients in the KTZ-naïve cohort (8.5%) and two in the KTZ-switch cohort (3.3%) developed liver injury, considered related to KTZ in three cases (all KTZ-naïve in the first month of treatment). Five patients had mild liver function abnormalities at baseline and two had proven liver metastases. Two patients recovered on discontinuation of KTZ and the remaining patient died of unrelated causes.

CONCLUSIONS

These findings highlight the need for close monitoring of liver enzymes especially during the first six months of treatment. Liver enzyme abnormalities usually occurred within four weeks were asymptomatic and could be reversed on timely discontinuation of KTZ.

MANAGEMENT OF ENDOCRINE DISEASE: Can we cure Cushing's disease? A personal view

One of today's challenges in endocrinology is the treatment of Cushing's disease: Although pituitary surgery has the potential to 'cure' the patient and restore a completely normal pituitary adrenal axis, there are immediate failures and late recurrences that will ultimately require alternate therapeutic approaches. Their high number is in direct correlation with their serious limitations and they all appear to be 'default options'. This 'personal view' tries to shed some light on the inescapable difficulties of the current treatments of Cushing's disease and to provide some optimistic view for the future where the pituitary adenoma should be the 'reasonable obsession' of a successful therapeutist.

A review of Cushing's disease treatment by the Department of Neuroendocrinology of the Brazilian Society of Endocrinology and Metabolism

The treatment objectives for a patient with Cushing's disease (CD) are remission of hypercortisolism, adequate management of co-morbidities, restoration of the hypothalamic-pituitary-adrenal axis, preservation of fertility and pituitary function, and improvement of visual defects in cases of macroadenomas with suprasellar extension. Transsphenoidal pituitary surgery is the main treatment option for the majority of cases, even in macroadenomas with low probability of remission. In cases of surgical failure, another subsequent pituitary surgery might be indicated in cases with persistent tumor imaging at post surgical magnetic resonance imaging (MRI) and/or pathology analysis of adrenocorticotropic hormone-positive (ACTH+) positive pituitary adenoma in the first procedure. Medical treatment, radiotherapy and adrenalectomy are the other options when transsphenoidal pituitary surgery fails. There are several options of medical treatment, although cabergoline and ketoconazole are the most commonly used alone or in combination. Novel treatments are also addressed in this review. Different therapeutic approaches are frequently needed on an individual basis, both before and, particularly, after surgery, and they should be individualized. The objective of the present review is to provide the necessary information to achieve a more effective treatment for CD. It is recommended that patients with CD be followed at tertiary care centers with experience in treating this condition.

Are Cushing's disease patients curable?

Treatment of Cushing's disease remains a challenge. Whereas pituitary surgery can "cure" the patient and restore a completely normal pituitary adrenal axis, there are immediate failures and late recurrences which ultimately require alternate therapeutic approaches. These are numerous, but so are their drawbacks, and all appear to be "default options". For the future, pituitary adenoma has to remain the "reasonable obsession" of efficient and optimistic therapists….

Preoperative medical treatment in Cushing's syndrome: frequency of use and its impact on postoperative assessment: data from ERCUSYN

BACKGROUND

Surgery is the definitive treatment of Cushing's syndrome (CS) but medications may also be used as a first-line therapy. Whether preoperative medical treatment (PMT) affects postoperative outcome remains controversial.

OBJECTIVE

(1) Evaluate how frequently PMT is given to CS patients across Europe; (2) examine differences in preoperative characteristics of patients who receive PMT and those who undergo primary surgery and (3) determine if PMT influences postoperative outcome in pituitary-dependent CS (PIT-CS).

PATIENTS AND METHODS

1143 CS patients entered into the ERCUSYN database from 57 centers in 26 countries. Sixty-nine percent had PIT-CS, 25% adrenal-dependent CS (ADR-CS), 5% CS from an ectopic source (ECT-CS) and 1% were classified as having CS from other causes (OTH-CS).

RESULTS

Twenty per cent of patients took PMT. ECT-CS and PIT-CS were more likely to receive PMT compared to ADR-CS (P < 0.001). Most commonly used drugs were ketoconazole (62%), metyrapone (16%) and a combination of both (12%). Median (interquartile range) duration of PMT was 109 (98) days. PIT-CS patients treated with PMT had more severe clinical features at diagnosis and poorer quality of life compared to those undergoing primary surgery (SX) (P < 0.05). Within 7 days of surgery, PIT-CS patients treated with PMT were more likely to have normal cortisol (P < 0.01) and a lower remission rate (P < 0.01). Within 6 months of surgery, no differences in morbidity or remission rates were observed between SX and PMT groups.

CONCLUSIONS

PMT may confound the interpretation of immediate postoperative outcome. Follow-up is recommended to definitely evaluate surgical results.

Management of hormone-secreting pituitary adenomas

Pituitary adenomas are one of the most common primary central nervous system tumors and have an estimated prevalence of 17%. Approximately half of pituitary adenomas secrete distinct pituitary hormones (most often prolactin, growth hormone, or adrenocorticotropic hormone). While these tumors are histologically benign, they have potent endocrine effects that lead to significant morbidity and shortened lifespan. Because of their pathophysiologic endocrine secretion and anatomic location near critical neural/vascular structures, hormone-secreting pituitary adenomas require defined management paradigms that can include relief of mass effect and biochemical remission. Management of hormone-secreting pituitary adenomas involves a multidisciplinary approach that can incorporate surgical, medical, and/or radiation therapies. Early and effective treatment of hormone-secreting pituitary adenomas can reduce morbidity and mortality. Consequently, understanding clinical features as well as therapeutic options in the context of the specific biological features of each type of hormone-secreting pituitary adenoma is critical for optimal management.

Posaconazole-Induced Adrenal Insufficiency in a Case of Chronic Myelomonocytic Leukemia

Introduction

Posaconazole is an azole used in treatment and prophylaxis of a broad spectrum of fungal infections. Antifungals such as ketoconazole have been shown to cause primary adrenal insufficiency (AI) as a result of direct inhibition on the steroidogenesis pathway. There is only one reported case of primary AI induced by posaconazole in a patient with mucormycosis. We report a case of posaconazole-related primary AI.

Case

A 63-year-old man with chronic myelomonocytic leukemia was admitted for fatigue and intermittent nausea and vomiting. He had recently discontinued prophylactic posaconazole 300 mg daily. He was assessed for AI with a morning cortisol of 1.9 mcg/dL followed by a failed cosyntropin stimulation (CS) test. Adrenocorticotropic hormone (ACTH) level was 154.6 pg/mL with negative 21-hydroxylase antibodies. The patient's symptoms improved with initiation of hydrocortisone and fludrocortisone. One year after discontinuation of posaconazole, he underwent a repeat CS test which showed normal adrenal function with normal ACTH at 34.1 pg/mL.

Conclusion

In this case, we demonstrate that prolonged use of posaconazole is associated with primary AI. As use of posaconazole increases, knowledge of the potential risk of AI is important and must be included in the differential diagnosis when these patients present with hypotension, hypoglycemia, and failure to thrive.

Cell Cycle Regulators and Lineage-Specific Therapeutic Targets for Cushing Disease

Cell cycle proteins are critical to pituitary development, but their contribution to lineage-specific tumorigenesis has not been well-elucidated. Emerging evidence from in vitro human tumor analysis and transgenic mouse models indicates that G1/S-related cell cycle proteins, particularly cyclin E, p27, Rb, and E2F1, drive molecular mechanisms that underlie corticotroph-specific differentiation and development of Cushing disease. The aim of this review is to summarize the literature and discuss the complex role of cell cycle regulation in Cushing disease, with a focus on identifying potential targets for therapeutic intervention in patients with these tumors.

New Insights in Cushing Disease Treatment With Focus on a Derivative of Vitamin A

Cushing's disease (CD) is an endocrine disorder originated by a corticotroph tumor. It is linked with high mortality and morbidity due to chronic hypercortisolism. Treatment goals are to control cortisol excess and achieve long-term remission, therefore, reducing both complications and patient's mortality. First-line of treatment for CD is pituitary's surgery. However, 30% of patients who undergo surgery experience recurrence in long-term follow-up. Persistent or recurrent CD demands second-line treatments, such as pituitary radiotherapy, adrenal surgery, and/or pharmacological therapy. The latter plays a key role in cortisol excess control. Its targets are inhibition of adrenocorticotropic hormone (ACTH) production, inhibition of adrenal steroidogenesis, or antagonism of cortisol action at its peripheral receptor. Retinoic acid (RA) is a metabolic product of vitamin A (retinol) and has been studied for its antiproliferative effects on corticotroph tumor cells. It has been shown that this drug regulates the expression of pro-opiomelanocortin (POMC), ACTH secretion, and tumor growth in corticotroph tumor mouse cell lines and in the nude mice experimental model, via inhibition of POMC transcription. It has been shown to result in tumor reduction, normalization of cortisol levels and clinical improvement in dogs treated with RA for 6 months. The orphan nuclear receptor COUP-TFI is expressed in normal corticotroph cells, but not in corticotroph tumoral cells, and inhibits RA pathways. A first clinical human study demonstrated clinical and biochemical effectiveness in 5/7 patients treated with RA for a period of up to 12 months. In a recent second clinical trial, 25% of 16 patients achieved eucortisolemia, and all achieved a cortisol reduction after 6- to 12-month treatment. The goal of this review is to discuss in the context of the available and future pharmacological treatments of CD, RA mechanisms of action on corticotroph tumor cells, and future perspectives, focusing on potential clinical implementation.

Diabetes Mellitus Secondary to Cushing's Disease

Associated with important comorbidities that significantly reduce patients' overall wellbeing and life expectancy, Cushing's disease (CD) is the most common cause of endogenous hypercortisolism. Glucocorticoid excess can lead to diabetes, and although its prevalence is probably underestimated, up to 50% of patients with CD have varying degrees of altered glucose metabolism. Fasting glycemia may nevertheless be normal in some patients in whom glucocorticoid excess leads primarily to higher postprandial glucose levels. An oral glucose tolerance test should thus be performed in all CD patients to identify glucose metabolism abnormalities. Since diabetes mellitus (DM) is a consequence of cortisol excess, treating CD also serves to alleviate impaired glucose metabolism. Although transsphenoidal pituitary surgery remains the first-line treatment for CD, it is not always effective and other treatment strategies may be necessary. This work examines the main features of DM secondary to CD and focuses on antidiabetic drugs and how cortisol-lowering medication affects glucose metabolism.

Dimethoxy-etomidate: A Nonhypnotic Etomidate Analog that Potently Inhibits Steroidogenesis

Cushing's syndrome is characterized by the overproduction of adrenocortical steroids. Steroidogenesis inhibitors are mainstays of medical therapy for Cushing's syndrome; unfortunately, adverse side effects and treatment failures are common with currently available drugs. The general anesthetic induction agent etomidate is among the most potent inhibitors of adrenocortical steroidogenesis. However, its use as a treatment of Cushing's syndrome is complicated by its sedative-hypnotic activity and ability to produce myoclonus, central nervous system actions thought to be mediated by the GABA_A receptor. Here, we describe the pharmacology of the novel etomidate analog (R)-ethyl 1-(1-(3,5-dimethoxyphenyl)ethyl)-1H-imidazole-5-carboxylate (dimethoxy-etomidate). In contrast to etomidate, dimethoxy-etomidate minimally enhanced GABA-evoked GABA_A receptor-mediated currents even at a near-saturating aqueous concentration. In Sprague-Dawley rats, dimethoxy-etomidate's potency for producing loss of righting reflexes-an animal model of sedation/hypnosis-was 2 orders of magnitude lower than that of etomidate, and it did not produce myoclonus. However, similar to etomidate, dimethoxy-etomidate potently suppressed adrenocortical steroid synthesis primarily by inhibiting 11β-hydroxylase. [³H]etomidate binding to rat adrenocortical membranes was inhibited by dimethoxy-etomidate in a biphasic manner with IC₅₀ values of 8.2 and 3970 nM, whereas that by etomidate was monophasic with an IC₅₀ of 22 nM. Our results demonstrate that, similar to etomidate, dimethoxy-etomidate potently and dose-dependently suppresses adrenocortical steroid synthesis by inhibiting 11β-hydroxylase. However, it is essentially devoid of etomidate's GABA_A receptor positive modulatory and sedative-hypnotic activities and produces no myoclonus, providing proof of concept for the design of etomidate analogs without important central nervous system actions for the pharmacologic treatment of Cushing's syndrome.

A polymorphism in the CYP17A1 gene influences the therapeutic response to steroidogenesis inhibitors in Cushing's syndrome

CONTEXT

Steroidogenesis inhibitors, such as ketoconazole (KTZ) and metyrapone (MTP), are used to lower hypercortisolism in patients with Cushing's syndrome (CS). Cortisol normalization is not reached in all patients taking these medications.

OBJECTIVE

To test the hypothesis that variants in genes affecting steroidogenesis contribute to different responses to KTZ and/or MTP in patients with CS.

PATIENTS AND METHODS

Fifty-four CS patients (46 women; mean [±SD] age, 39.7±12.7; 83% with Cushing's disease [CD] and 17% with an adrenal adenoma) preoperatively treated with KTZ (20%), MTP (37%) or a combination of both (43%). Thirty-nine of these (72%) were described in a previous study investigating the outcome of preoperative treatment with KTZ or MTP in CS patients. Following single-nucleotide polymorphisms (SNPs) were analysed: rs6410 (CYP11B1 gene), rs1799998 and rs4546 (CYP11B2 gene), and rs6163 (CYP17A1 gene). The associations between SNPs and cortisol levels at the end of medical treatment were evaluated.

RESULTS

Normalization of urinary free cortisol (UFC) was achieved in 50% of patients after 5 months of treatment. Patients carrying the CC genotype of SNP rs6163 were more likely to be controlled than AC/AA (OR 0.25 [95%CI, 0.075-0.88]; P=.031). When only patients reaching eucortisolism after medical treatment were analysed, median interquartile range (IQR) duration of treatment was shorter in patients carrying the CC genotype of SNP rs6163 as compared to AA/AC carriers (4 [4.57] months vs 5.2 [6.1] months; P=.026).

CONCLUSIONS

A polymorphism in the CYP17A1 gene was associated with the response to steroidogenesis inhibitors in CS. Genetic differences in the steroidogenic enzymes might account for inter-individual variations in the responsiveness to adrenal-blocking agents.

Stereotactic Radiosurgery for Cushing Disease: Results of an International, Multicenter Study

CONTEXT

Cushing disease (CD) due to adrenocorticotropic hormone-secreting pituitary tumors can be a management challenge.

OBJECTIVE

To better understand the outcomes of stereotactic radiosurgery (SRS) for CD and define its role in management.

DESIGN

International, multicenter, retrospective cohort analysis.

SETTING

Ten medical centers participating in the International Gamma Knife Research Foundation.

PATIENTS

Patients with CD with >6 months endocrine follow-up.

INTERVENTION

SRS using Gamma Knife radiosurgery.

MAIN OUTCOME MEASURES

The primary outcome was control of hypercortisolism (defined as normalization of free urinary cortisol). Radiologic response and adverse radiation effects (AREs) were recorded.

RESULTS

In total, 278 patients met inclusion criteria, with a mean follow-up of 5.6 years (0.5 to 20.5 years). Twenty-two patients received SRS as a primary treatment of CD. Mean margin dose was 23.7 Gy. Cumulative initial control of hypercortisolism was 80% at 10 years. Mean time to cortisol normalization was 14.5 months. Recurrences occurred in 18% with initial cortisol normalization. Overall, the rate of durable control of hypercortisolism was 64% at 10 years and 68% among patients who received SRS as a primary treatment. AREs included hypopituitarism (25%) and cranial neuropathy (3%). Visual deficits were related to treatment of tumor within the suprasellar cistern (P = 0.01), whereas both visual (P < 0.0001) and nonvisual cranial neuropathy (P = 0.02) were related to prior pituitary irradiation.

CONCLUSIONS

SRS for CD is well tolerated and frequently results in control of hypercortisolism. However, recurrences can occur. SRS should be considered for patients with persistent hypercortisolism after pituitary surgery and as a primary treatment in those unfit for surgery. Long-term endocrine follow-up is essential after SRS.

Effects of Ketoconazole on the Pharmacokinetics of Mifepristone, a Competitive Glucocorticoid Receptor Antagonist, in Healthy Men

Introduction

Mifepristone, a competitive glucocorticoid receptor antagonist approved for Cushing syndrome, and ketoconazole, an antifungal and steroidogenesis inhibitor, are both inhibitors of and substrates for cytochrome P450 (CYP3A4). This study evaluated the pharmacokinetic effects of concomitant ketoconazole, a strong CYP3A4 inhibitor, on mifepristone.

Methods

In an open-label, two-period, single-center study, healthy adult men received mifepristone 600 mg orally daily for 12 days (period 1) followed by mifepristone 600 mg daily plus ketoconazole 200 mg orally twice daily for 5 days (period 2). Serial pharmacokinetic blood samples were collected predose and over 24 h postdose on days 12 (period 1) and 17 (period 2). A cross-study comparison (using data on file) further examined whether systemic exposure to mifepristone plus ketoconazole exceeded the exposure following mifepristone 1200 mg orally administered for 7 days.

Results

Sixteen subjects were enrolled and 14 completed the study. Concomitant administration with ketoconazole increased the systemic exposure to mifepristone, based on geometric least squares mean ratios, by 28% for C_max and 38% for AUC_0–24. This increase was 85% and 87% of the exposure observed following mifepristone’s highest label dose of 1200 mg/day for C_max and AUC_0–24, respectively. Adverse events (AEs) were reported in 56.3% (9/16) of subjects during administration of mifepristone alone and in 57.1% (8/14) during combination with ketoconazole. No serious AEs were reported.

Conclusion

Systemic exposure to mifepristone increased following multiple doses of mifepristone 600 mg daily plus ketoconazole 200 mg twice daily. Little to no increase in AEs occurred. Dose adjustment of mifepristone may be needed when given with ketoconazole.

Funding

Corcept Therapeutics.

AN INDIVIDUALIZED APPROACH TO THE EVALUATION OF CUSHING SYNDROME

Cushing syndrome (CS) is caused by chronic exposure to excess glucocorticoids. Early recognition and treatment of hypercortisolemia can lead to decreased morbidity and mortality. The diagnosis of CS and thereafter, establishing the cause can often be difficult, especially in patients with mild and cyclic hypercortisolism. Surgical excision of the cause of excess glucocorticoids is the optimal treatment for CS. Medical therapy (steroidogenesis inhibitors, medications that decrease adrenocorticotropic hormone [ACTH] levels or glucocorticoid antagonists) and pituitary radiotherapy may be needed as adjunctive treatment modalities in patients with residual, recurrent or metastatic disease, in preparation for surgery, or when surgery is contraindicated. A multidisciplinary team approach, individualized treatment plan and long-term follow-up are important for optimal management of hypercortisolemia and the comorbidities associated with CS.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone; BIPSS = bilateral inferior petrosal sinus sampling; CBG = corticosteroid-binding globulin; CD = Cushing disease; CRH = corticotropin-releasing hormone; CS = Cushing syndrome; Dex = dexamethasone; DST = dexamethasone suppression test; EAS = ectopic ACTH syndrome; FDA = U.S. Food & Drug Administration; HDDST = high-dose DST; IPS/P = inferior petrosal sinus to peripheral; MRI = magnetic resonance imaging; NET = neuroendocrine tumor; PET = positron emission tomography; UFC = urinary free cortisol.

Long-term treatment of Cushing's disease with pasireotide: 5-year results from an open-label extension study of a Phase III trial

BACKGROUND

Treating hypercortisolism in patients with Cushing's disease after failed surgery often requires chronic medication, underlining the need for therapies with favourable long-term efficacy and safety profiles.

METHODS

In a randomised, double-blind study, 162 adult patients with persistent/recurrent or de novo Cushing's disease received pasireotide. Patients with mean urinary free cortisol at/below the upper limit of normal or clinical benefit at month 12 could continue receiving pasireotide during an open-ended, open-label phase, the outcomes of which are described herein.

RESULTS

Sixteen patients received 5 years of pasireotide treatment. Among these, median (95% confidence interval) percentage change from baseline in mean urinary free cortisol was -82.6% (-89.0, -41.9) and -81.8% (-89.8, -67.4) at months 12 and 60. Eleven patients had mean urinary free cortisol ≤ upper limit of normal at month 60. Improvements in clinical signs were sustained during long-term treatment. The safety profile of pasireotide at 5 years was similar to that reported after 12 months. Fifteen of 16 patients experienced a hyperglycaemia-related adverse event; glycated haemoglobin levels were stable between months 6 and 60. Adverse events related to hyperglycaemia, bradycardia, gallbladder/biliary tract, and liver safety were most likely to first occur by month 6; adverse event severity did not tend to worsen over time.

CONCLUSIONS

This represents the longest prospective trial of a medical therapy for Cushing's disease to date. A subset of patients treated with pasireotide maintained biochemical and clinical improvements for 5 years, with no new safety signals emerging. These data support the use of pasireotide as an effective long-term therapy for some patients with Cushing's disease.

Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.

Recent Progress in the Medical Therapy of Pituitary Tumors

Management of pituitary tumors is multidisciplinary, with medical therapy playing an increasingly important role. With the exception of prolactin-secreting tumors, surgery is still considered the first-line treatment for the majority of pituitary adenomas. However, medical/pharmacological therapy plays an important role in controlling hormone-producing pituitary adenomas, especially for patients with acromegaly and Cushing disease (CD). In the case of non-functioning pituitary adenomas (NFAs), pharmacological therapy plays a minor role, the main objective of which is to reduce tumor growth, but this role requires further studies. For pituitary carcinomas and atypical adenomas, medical therapy, including chemotherapy, acts as an adjuvant to surgery and radiation therapy, which is often required to control these aggressive tumors. In the last decade, knowledge about the pathophysiological mechanisms of various pituitary adenomas has increased, thus novel medical therapies that target specific pathways implicated in tumor synthesis and hormonal over secretion are now available. Advancement in patient selection and determination of prognostic factors has also helped to individualize therapy for patients with pituitary tumors. Improvements in biochemical and "tumor mass" disease control can positively affect patient quality of life, comorbidities and overall survival. In this review, the medical armamentarium for treating CD, acromegaly, prolactinomas, NFA, and carcinomas/aggressive atypical adenomas will be presented. Pharmacological therapies, including doses, mode of administration, efficacy, adverse effects, and use in special circumstances are provided. Medical therapies currently under clinical investigation are also briefly discussed.

Drug Interaction Potential of Osilodrostat (LCI699) Based on Its Effect on the Pharmacokinetics of Probe Drugs of Cytochrome P450 Enzymes in Healthy Adults

BACKGROUND AND OBJECTIVES

Osilodrostat (LCI699) is an adrenal steroidogenesis inhibitor currently in late-phase clinical development as a potential treatment for Cushing's disease. This study evaluated the inhibitory effect of osilodrostat on the pharmacokinetics of probe substrates of the cytochrome P450 (CYP) enzymes CYP1A2, CYP2C19, CYP2D6, and CYP3A4.

METHODS

Healthy adult volunteers received single-dose cocktail probe substrates [caffeine (100 mg), omeprazole (20 mg), dextromethorphan (30 mg), and midazolam (2 mg)] followed by a 6-day washout. Subjects then received a single dose of osilodrostat 50 mg followed by a single dose of cocktail probe substrates.

RESULTS

Nineteen of twenty subjects (ten were male) completed the study. Mean age, body weight, and body mass index were 41.8 years, 73.0 kg, and 24.4 kg/m². Geometric mean ratio of the area under the concentration-time curve from time zero to the last measureable concentration and 90% confidence intervals of probe substrate exposure with osilodrostat were: caffeine (CYP1A2 probe substrate), 2.33 (2.10-2.59); omeprazole (CYP2C19), 1.91 (1.74-2.11); dextromethorphan (CYP2D6), 1.48 (1.34-1.63); and midazolam (CYP3A4/5), 1.50 (1.41-1.60). Corresponding values for geometric mean ratio of maximum plasma concentration (90% confidence interval) for the change in substrate exposure were 1.07 (0.988-1.15), 1.61 (1.40-1.84), 1.35 (1.21-1.50), and 1.47 (1.32-1.62).

CONCLUSIONS

Osilodrostat is a moderate inhibitor of CYP1A2 and CYP2C19 and a weak inhibitor of CYP2D6 and the most clinically important CYP enzyme, CYP3A4. Osilodrostat is unlikely to significantly increase the exposures of other medications cleared by CYP3A4. These findings are clinically relevant given that Cushing's disease is a chronic condition often requiring multiple medications and that most other therapies have significant drug interaction potential.

CYP3A4 Induction by Rifampin: An Alternative Pathway for Vitamin D Inactivation in Patients With CYP24A1 Mutations

Context

The P450 enzyme CYP24A1 is the principal inactivator of vitamin D metabolites. Biallelic loss-of-function mutations in CYP24A1 are associated with elevated serum levels of 1,25-dihydroxyvitamin D3 with consequent hypercalcemia and hypercalciuria and represent the most common form of idiopathic infantile hypercalcemia (IIH). Current management strategies for this condition include a low-calcium diet, reduced dietary vitamin D intake, and limited sunlight exposure. CYP3A4 is a P450 enzyme that inactivates many drugs and xenobiotics and may represent an alternative pathway for inactivation of vitamin D metabolites.

Objective

Our goal was to determine if rifampin, a potent inducer of CYP3A4, can normalize mineral metabolism in patients with IIH due to mutations in CYP24A1.

Methods

We treated two patients with IIH with daily rifampin (10 mg/kg/d, up to a maximum of 600 mg). Serum calcium, phosphorus, parathyroid hormone (PTH), liver, and adrenal function and vitamin D metabolites, as well as urinary calcium excretion, were monitored during treatment of up to 13 months.

Results

Prior to treatment, both patients had hypercalcemia, hypercalciuria, and nephrocalcinosis with elevated serum 1,25-dihydroxyvitamin D3 and suppressed serum PTH. Daily treatment with rifampin was well tolerated and led to normalization or improvement in all clinical and biochemical parameters.

Conclusion

These observations suggest that rifampin-induced overexpression of CYP3A4 provides an alternative pathway for inactivation of vitamin D metabolites in patients who lack CYP24A1 function.

Evaluation of Evidence of Adrenal Insufficiency in Trials of Normocortisolemic Patients Treated With Mifepristone

Context:

Adrenal insufficiency (AI) is an important medical concern for clinicians when normocortisolemia is achieved during treatment of endogenous Cushing syndrome (CS).

Objective:

To examine symptoms of potential AI in a large population of normocortisolemic patients without CS treated with mifepristone, a glucocorticoid receptor antagonist indicated for the treatment of patients with CS.

Methods:

We conducted a pooled safety analysis of five phase 3, placebo-controlled clinical trials of normocortisolemic adults without CS but diagnosed with psychotic depression (n = 1460). Patients were treated with once-daily mifepristone 300 mg (n = 110), 600 mg (n = 471), or 1200 mg (n = 252), or placebo (n = 627) administered for 7 consecutive days. All study investigators were trained and instructed to assess for the development of AI and to report all adverse events (AEs) at each clinic visit. The incidence of (1) AI or similar terminologies and that of (2) ≥3 concurrent symptoms that could be associated with AI was evaluated.

Results:

Mean serum cortisol and adrenocorticotropic hormone levels increased dose dependently with mifepristone treatment. There were no reports of AI and no significant differences between the mifepristone-treated and placebo groups in the incidence of patients having ≥3 AEs that could be associated with AI.

Conclusions:

This large pooled analysis of normocortisolemic patients without CS found no cases of AI and no differences between mifepristone therapy and placebo in the incidence of symptom combinations mimicking AI, even at the highest (1200 mg) dose. These findings further add clinically important insights to the safety and tolerability profile of mifepristone therapy.

MRI follow-up is unnecessary in patients with macroprolactinomas and long-term normal prolactin levels on dopamine agonist treatment

OBJECTIVE

Both antitumor and antisecretory efficacies of dopamine agonists (DA) make them the first-line treatment of macroprolactinomas. However, there is no guideline for MRI follow-up once prolactin is controlled. The aim of our study was to determine whether a regular MRI follow-up was necessary in patients with long-term normal prolactin levels under DA.

PATIENTS AND METHODS

We conducted a retrospective multicenter study (Marseille, Paris La Pitie Salpetriere and Nancy, France; Liege, Belgium) including patients with macroprolactinomas (largest diameter: >10 mm and baseline prolactin level: >100 ng/mL) treated by dopamine agonists, and regularly followed (pituitary MRI and prolactin levels) during at least 48 months once normal prolactin level was obtained.

RESULTS

In total, 115 patients were included (63 men and 52 women; mean age at diagnosis: 36.3 years). Mean baseline prolactin level was 2224 ± 6839 ng/mL. No significant increase of tumor volume was observed during the follow-up. Of the 21 patients (18%) who presented asymptomatic hemorrhagic changes of the macroprolactinoma on MRI, 2 had a tumor increase (2 and 7 mm in the largest size). Both were treated by cabergoline (1 mg/week) with normal prolactin levels obtained for 6 and 24 months. For both patients, no further growth was observed on MRI during follow-up at the same dose of cabergoline.

CONCLUSION

No significant increase of tumor size was observed in our patients with controlled prolactin levels on DA. MRI follow-up thus appears unnecessary in patients with biologically controlled macroprolactinomas.

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

OBJECTIVE

The efficacy of cabergoline in Cushing's disease (CD) is controversial. The aim of this study was to assess the efficacy and tolerability of cabergoline in a large contemporary cohort of patients with CD.

DESIGN

We conducted a retrospective multicenter study from thirteen French and Belgian university hospitals.

METHODS

Sixty-two patients with CD received cabergoline monotherapy or add-on therapy. Symptom score, biological markers of hypercortisolism and adverse effects were recorded.

RESULTS

Twenty-one (40%) of 53 patients who received cabergoline monotherapy had normal urinary free cortisol (UFC) values within 12 months (complete responders), and five of these patients developed corticotropic insufficiency. The fall in UFC was associated with significant reductions in midnight cortisol and plasma ACTH, and with clinical improvement. Compared to other patients, complete responders had similar median baseline UFC (2.0 vs 2.5xULN) and plasma prolactin concentrations but received lower doses of cabergoline (1.5 vs 3.5 mg/week, P < 0.05). During long-term treatment (>12 months), cabergoline was withdrawn in 28% of complete responders because of treatment escape or intolerance. Overall, sustained control of hypercortisolism was obtained in 23% of patients for 32.5 months (19-105). Nine patients on steroidogenesis inhibitors received cabergoline add-on therapy for 19 months (1-240). Hypercortisolism was controlled in 56% of these patients during the first year of treatment with cabergoline at 1.0 mg/week (0.5-3.5).

CONCLUSIONS

About 20-25% of CD patients are good responders to cabergoline therapy allowing long-term control of hypercortisolism at relatively low dosages and with acceptable tolerability. No single parameter, including the baseline UFC and prolactin levels, predicted the response to cabergoline.

Multiple Salivary Cortisol Measurements Are a Useful Tool to Optimize Metyrapone Treatment in Patients with Cushing's Syndromes Treatment: Case Presentations

Measuring salivary cortisol is both convenient and non-invasive for patients; however, its usefulness as a marker for monitoring medical therapy has not yet been established. The aim of this study was to assess the utility of multiple salivary cortisol measurements in patients with Cushing's syndrome (CS) during medical therapy. Six patients with CS (three with cortisol-secreting adrenocortical adenoma and three with ACTH-secreting pituitary adenoma) were recruited. Samples for morning serum cortisol, urinary free cortisol (UFC), and multiple salivary cortisol levels were collected before and during metyrapone treatment. The area under the curve (AUC) and mean value (MV) of daily salivary cortisol levels were calculated. In five out of six patients, UFC were normalized; however, multiple salivary cortisol measurements revealed an impaired diurnal cortisol rhythm in these patients. To verify the usefulness of multiple salivary cortisol measurements, we performed a prospective case study of a patient in whom the excess secretion of cortisol was not controlled (UFC 211 μg/day) with 2,250 mg/day in four divided doses of metyrapone. Multiple measurements of salivary cortisol revealed that cortisol levels elevated before the next administration. Accordingly, we shortened the interval by increasing the number of administration from four to five times per day, with a slight increment of daily dose of 2,500 mg. These optimizations resulted in a drastic improvement of diurnal pattern as well as UFC level (101 μg/day). Changes in both the MV and AUC of salivary cortisol levels were more correlated with those in UFC levels (Correlation coefficient 0.75, p = 0.007, and 0.70, p = 0.017) than those in the morning serum cortisol levels (0.42, p = 0.200), indicating that multiple salivary cortisol measurements reflect more precisely the excess secretion of cortisol. Our preliminary data suggest that multiple salivary cortisol measurements can be a useful tool to visualize the diurnal cortisol rhythm and to determine the dose and timing of metyrapone during the treatment in patients with CS.