ICE/ENDO 2014: 16th International Congress of Endocrinology and The Endocrine Society's 96th Annual Meeting:
New Medication Approaches to Treat Cushing's Syndrome
“The optimal treatment of Cushing’s syndrome is tailored to the cause,” stated Lynette K. Nieman, MD of the National Institutes of Health in Bethesda, MD. In her presentation, Dr. Nieman discussed treatment approaches and was quick to point out that there are many different ways the clinician can approach treatment of Cushing’s syndrome.
Cushing’s syndrome is a symptom complex that reflects excessive tissue exposure to cortisol. If untreated, mortality increases—usually thrombotic—such as heart attack, stroke, pulmonary emboli, and many different infections.
“The primary adrenal causes are treated with unilateral or bilateral adrenalectomy depending on the etiology. The adrenocorticotropin (ACTH)-dependent forms include tumors located in the pituitary gland or in an ectopic location. Surgical resection is the ideal treatment for these as it removes the source of excess ACTH yet leaves the normal hypothalamic-pituitary-adrenal axis intact,” stated Dr. Nieman. Barriers to medications include not being available in all countries.
Cabergoline, pasireotide, and mifepristone are three new drugs Dr. Nieman described in her materials, and discussed during case presentations.
- Cabergoline (oral agent) is a dopamine agonist, and about 80% of these tumors have dopamine agonist receptors. In Cushing’s disease, it is an off-label use. In a study of 20 patients who underwent transsphenoidal surgery, 10 subjects had normal urine-free cortisol (UFC) at 12 months; 8 were controlled at 24 months; and, 2 discontinued the study.
- Pasireotide (parenteral agent) is a somatostatin analog and is indicated in the treatment of adults with Cushing’s disease when surgery is not an option or fails. Approval by the US Food and Drug Administration (FDA) was based on a large phase 3 study of 162 patients with recurrent or persistent Cushing’s disease. Patients were treated with 600 or 900 µg subcutaneous twice per day.
- Mifepristone was FDA-approved in 2012 to control hyperglycemia secondary to hypercortisolism in adults with endogenous Cushing’s syndrome who have failed operative intervention, or were not surgical candidates. Approval was based on an open-label study of 50 patients with diabetes/glucose intolerance and/or hypertension—most had Cushing’s disease. Mifepristone antagonizes cortisol action.