Pituitary Disorders Medical Treatment of Cushing’s Disease with Pasireotide

Cushing’s disease is the most common form of endogenous Cushing’s syndrome and results from excess adrenocorticotropic hormone (ACTH) production by a corticotroph pituitary adenoma. Transsphenoidal surgical removal of the corticotroph adenoma is the treatment of choice for patients with Cushing’s disease. However, despite advances in surgery, complete tumour removal is sometimes impossible and eventual disease recurrence occurs later even in patients who achieved an initial remission. Medical therapy is one of the second-line options, which can provide a primary or adjunctive role if the patient cannot safely undergo pituitary surgery, if surgery fails, or if the tumour recurs. However, until recently, few effective therapeutic options existed. Somatostatin receptors in the corticotroph tumours have been identified as potential therapeutic targets for Cushing’s disease. Pasireotide is a novel somatostatin analogue which has high affinity for these receptors. In a recent Phase III clinical trial, pasireotide treatment was demonstrated to significantly reduce elevated cortisol levels in patients with Cushing’s disease achieving normalisation of urinary free cortisol (UFC) levels in subset of patients and close to 50 % mean reduction in UFC levels were seen in the patients. Initial data also suggest that pasireotide could be highly effective as part of combined therapy for Cushing’s disease.