Effect of Pasireotide Long Acting Release (LAR) on Gonadotroph Adenomas

Gonadotroph adenomas are the most common pituitary macroadenomas. Currently no medical treatment as been found that decreases the size of these adenomas, so surgery is the only treatment. The reason to think that pasireotide might affect gonadotroph adenomas is that pasireotide binds avidly to somatostatin subtype 5 receptors, and gonadotroph adenomas express these receptors. For this study, three subjects who have gonadotroph adenomas, as judged by a macroadenoma of the pituitary and elevated serum FSH concentration, will be treated with a long-acting form of pasireotide once a month for one year. The effect of pasireotide on the size of the adenoma will be determined by MRI, and FSH secretion will be judged by the serum concentration.