Pituitary-directed medical therapy with pasireotide for a corticotroph macroadenoma: pituitary volume reduction and literature review

Hypercortisolism due to an ACTH-secreting pituitary adenoma (Cushing’s disease) is a chronic condition associated with high morbidity and mortality if inadequately managed. Pasireotide is a multireceptor-targeted somatostatin analogue and is the only approved medical therapy for Cushing’s disease that treats the underlying cause of the disorder. This paper reviews the available literature for medical-therapy-induced adenoma volume reduction in patients with Cushing’s disease and reports the experience of a 53-year-old surgically, radiologically and medically naïve (de novo) female with a pituitary macroadenoma who declined surgery. This patient was treated with pasireotide as first-line therapy as part of the largest randomized Phase III study evaluating a medical therapy in patients with Cushing’s disease (SOM230B2305 trial). Subcutaneous pasireotide significantly decreased tumor volume, suppressed cortisol secretion, and improved clinical signs and symptoms of Cushing’s disease in this patient. Based on this experience, first-line pasireotide has the potential to achieve substantial tumor volume reduction in addition to significant improvements in cortisol levels and signs and symptoms in patients with Cushing’s disease for whom surgery is not an option.