Luiz Roberto Salgado

A 12-Month Phase 3 Study of Pasireotide in Cushing's Disease

BACKGROUND Cushings disease is associated with high morbidity and mortality. Pasireotide, a potential therapy, has a unique, broad somatostatin-receptor-binding profile, with high binding affinity for somatostatin-receptor subtype 5. METHODS In this double-blind, phase 3 study, we randomly assigned 162 adults with Cushings disease and a urinary free cortisol level of at least 1.5 times the upper limit of the normal range to receive subcutaneous pasireotide at a dose of 600 μg (82 patients) or 900 μg (80 patients) twice daily. Patients with urinary free cortisol not exceeding 2 times the upper limit of the normal range and not exceeding the baseline level at month 3 continued to receive their randomly assigned dose; all others received an additional 300 μg twice daily. The primary end point was a urinary free cortisol level at or below the upper limit of the normal range at month 6 without an increased dose. Open-label treatment continued through month 12. RESULTS Twelve of the 82 patients in the 600-μg group and 21 of the 80 patients in the 900-μg group met the primary end point. The median urinary free cortisol level decreased by approximately 50% by month 2 and remained stable in both groups. A normal urinary free cortisol level was achieved more frequently in patients with baseline levels not exceeding 5 times the upper limit of the normal range than in patients with higher baseline levels. Serum and salivary cortisol and plasma corticotropin levels decreased, and clinical signs and symptoms of Cushings disease diminished. Pasireotide was associated with hyperglycemia-related adverse events in 118 of 162 patients; other adverse events were similar to those associated with other somatostatin analogues. Despite declines in cortisol levels, blood glucose and glycated hemoglobin levels increased soon after treatment initiation and then stabilized; treatment with a glucose-lowering medication was initiated in 74 of 162 patients. CONCLUSIONS The significant decrease in cortisol levels in patients with Cushings disease who received pasireotide supports its potential use as a targeted treatment for corticotropin-secreting pituitary adenomas. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT00434148.).

Treatment of acromegaly with octreotide‐LAR: extensive experience in a Brazilian institution

Objective  Somatostatin analogues have become the mainstay of the medical treatment of acromegaly. The aim of our study was to evaluate the efficacy and tolerability of octreotide‐LAR (OCT‐LAR) treatment in acromegalic patients.

Medical Management of Pituitary Adenomas: The Special Case of Management of the Pregnant Woman

The development of efficacious surgical and medical therapies for pituitary adenomas as well as the improvement of hormone therapy for ovulation induction has made pregnancy possible for women harboring pituitary tumors. However, gestational risks due to the possibility of tumor growth during pregnancy, mainly in women with macroadenomas, raise a concern. Bromocriptine has a well-established role for prolactinoma treatment before and during pregnancy, even when a symptomatic tumor increase occurs. It can also be used in acromegaly, despite its poorer results. Somatostatin analogs have been used in acromegaly even during pregnancy with uneventful outcomes, but their safety in pregnancy is not well established, yet. The largest experience with medical treatment for Cushings disease during pregnancy involves metyrapone, a steroidogenesis inhibitor, without descriptions of congenital abnormalities. Concerning clinically non-functioning pituitary tumors, ovulation induction or even in vitro fertilization are frequently needed. The purpose of this review is to provide an update on therapeutic strategies to restore fertility as well as gestational and post-gestational management of patients with pituitary adenomas, focusing mainly on the role of medical treatment for different tumor types.

A study of patients with Nelson's syndrome

The prevalence of Nelsons syndrome has varied greatly, at least in part because of the variability of the diagnostic criteria employed by different authors. We define Nelsons syndrome as the presence of an enlarging pituitary tumour associated with elevated fasting plasma ACTH levels and hyperpigmentation in patients with Cushings disease after bilateral adrenalectomy. We have compared patients with Cushings disease who developed Nelsons syndrome after bilateral adrenalectomy with those who did not. Our objective was to find differences between the two groups which might predict the development of Nelsons syndrome.

High variability in baseline urinary free cortisol values in patients with Cushing's disease

Twenty‐four‐hour urinary free cortisol (UFC) sampling is commonly used to evaluate Cushings syndrome. Because there are few data on UFC variability in patients with active Cushings disease, we analysed baseline UFC in a large patient cohort with moderate‐to‐severe Cushings disease and assessed whether variability correlates with hypercortisolism severity. These data will help clinicians establish the minimum number of UFC samples required to obtain reliable data.

Pasireotide treatment significantly improves clinical signs and symptoms in patients with Cushing's disease: results from a Phase III study

Signs and symptoms of Cushings disease are associated with high burden of illness. In this analysis, we evaluated the effect of pasireotide treatment on signs and symptoms in patients with Cushings disease.

The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome

Objective   Bilateral inferior petrosal sinus sampling (BIPSS) with corticotrophin‐releasing hormone (CRH) stimulation is currently the gold standard test for the differential diagnosis of ACTH‐dependent Cushings syndrome. Reports on the use of desmopressin in this approach are limited. The aim of this study was to evaluate the use of desmopressin during BIPSS in a cohort of patients with ACTH‐dependent Cushings syndrome.

Role for postoperative cortisol response to desmopressin in predicting the risk for recurrent Cushing's disease

In the early postoperative period of Cushings disease patients, desmopressin may stimulate ACTH secretion in the remnant corticotrophic tumour, but not in nontumour suppressed cells.

Adrenocorticotropin levels do not change during early recovery of transsphenoidal surgery for ACTH-secreting pituitary tumors

In patients with ACTH-secreting pituitary tumor the peri-tumoral normal corticotrophs were supposed to be suppressed by cronic hypercortisolemia since frequently they develop transient secondary adrenal insufficiency after pituitary tumor resection and during early postoperative days. We evaluated the ACTH dynamics during transsphenoidal surgery in 16 patients with ACTHsecreting pituitary tumors (6 cured by surgery, 8 not cured Cushing’s disease patients and 1 cured by surgery and 1 not cured Nelson’s syndrome patients) and tested the hypothesis that in these patients, ACTH secretion from the peri-tumoral normal corticotrophs is inhibited and hence removal of the entire tumor should result in subtle postoperative reduction in plasma ACTH. Blood samples for ACTH determination were obtained from 14 Cushing’s disease patients immediately before pituitary gland manipulation and 10, 30, 60, 90, 120, 150 and 300 min after pituitary tumor resection and on postoperative day one. In Nelson’s syndrome patients the blood sample was obtained only after tumor removal. All patients received intravenous hydrocortisone during surgery and on the first postoperative day. Patients were considered cured by surgery if they presented adrenal insufficiency after hydrocortisone withdrawal. Mechanical pituitary manipulation induced increase in ACTH level. In all 14 Cushing’s disease patients (cured and not cured), mean plasma ACTH levels were significantly greater 10 min after pituitary tumor resection (54.4±12.8 pmol/l) than in the premanipulation period (ACTH=26.3±5.3 pmol/l) (p=0.005). In Cushing’s disease patients, the ACTH levels did not change significantly until 300 min after pituitary tumor resection either in those 6 patients cured by surgery (at 10 min after pituitary tumor resection ACTH was 54.4±12.8 pmol/l for all 14 Cushing’s disease patients and at 300 min after tumor removal ACTH was 39.0±12.6 pmol/l for cured and 41.3±15.7 pmol/l for not cured Cushing’s disease patients). The ACTH level also persisted high until 300 min after complete pituitary tumor resection in one cured patient with Nelson’s syndrome. ACTH level does not change in the early recovery period after ACTH-secreting pituitary tumor, even in those cured patients, and probably peri-tumoral normal corticotrophs are not completely suppressed by cronic hypercortisolemia (and acute glucocorticoid administration) when these patients are under intense stress, like transsphenoidal surgery. Mechanical pituitary manipulation may induce ACTH release in patients with ACTH-secreting pituitary tumors but probably does not interfere in the maintenance of high ACTH-levels during the early postoperative period, since ACTH half-life is only 8–15 min. In patients with ACTH-secreting pituitary tumors, the behavior of the human hypothalamic-pituitary-adrenal system during transsphenoidal surgery does not conform to the specifications of a negative feedback mechanism.

Association between tumoral GH-releasing peptide receptor type 1a mRNA expression and in vivo response to GH-releasing peptide-6 in ACTH-dependent Cushing's syndrome patients

OBJECTIVE GH secretagogues (GHS) produce exaggerated ACTH and cortisol responses in Cushings disease (CD) patients, attributable to their direct action on GH-releasing peptide receptor type 1a (GHSR-1a). However, there are no studies correlating the in vivo response to GHS and GHSR-1a mRNA expression in ACTH-dependent Cushings syndrome (CS) patients. The aim of this study is to correlate the patterns of ACTH and cortisol response to GH-releasing peptide-6 (GHRP-6) to GHSR-1a expression in ACTH-dependent CS patients. DESIGN Prospective study in a tertiary referral hospital center. Fifteen CD patients and two ectopic ACTH syndrome (EAS) patients were studied. METHODS Tumor fragments were submitted to RNA extraction, and GHSR-1a expression was studied through real-time qPCR and compared with normal tissue samples. The patients were also submitted to desmopressin test and vasopressin receptor type 1B (AVPR1B) mRNA analysis by qPCR. RESULTS GHSR-1a expression was similar in normal pituitary samples and in corticotrophic tumor samples. GHSR-1a expression was higher in patients (CD and EAS) presenting in vivo response to GHRP-6. Higher expression of AVPR1B was observed in the EAS patients responsive to desmopressin, as well as in corticotrophic tumors, as compared with normal pituitary samples, but no correlation between AVPR1B expression and response to desmopressin was observed in the CD patients. CONCLUSIONS Our results revealed a higher expression of GHSR-1a in the ACTH-dependent CS patients responsive to GHRP-6, suggesting an association between receptor gene expression and in vivo response to the secretagogue in both the CD and the EAS patients.