Pasireotide Therapy in Patients With Nelson's Syndrome

Inclusion Criteria: * To be verified at Visit one and confirmed at Visit two * Male or female patients aged 18-80 years * Signs and symptoms consistent with Nelson's Syndrome * Biochemistry consistent with Nelsons syndrome: failure to suppress plasma ACTH to less than 200 pg/ml at 2 hours following morning dose of hydrocortisone * Negative pregnancy test where applicable Exclusion Criteria: * Received any prior or current treatment with a pasireotide or other somatostatin analogue. * Requires surgery for recent significant deterioration in visual fields or other neurological signs related to tumour mass. * Liver disease such as cirrhosis, chronic active hepatitis or chronic persistent hepatitis, or persistent ALT, AST, alkaline phosphates 2X\> upper limit of normal, or total bilirubin 1.5X\> upper limit of normal. * Patients with symptomatic cholelithiasis * Abnormal clinical laboratory values considered by the Investigator to be clinically significant and which could affect the interpretation of the study results * QTcF interval as measured by ECG \>480msecs * Any current or prior medical condition that may, in the opinion of the Investigator, interfere with the conduct of the study or evaluation of the results. * Female patients who are pregnant or lactating, or of childbearing potential and not practising a medically acceptable method of birth control. Medically acceptable methods include including the oral contraceptive pill, intrauterine devices, mechanical methods (e.g. vaginal diaphragm, vaginal sponge, or condom with permicidal jelly). * History of alcohol or drug abuse in the sixmonth period prior to Visit 1, or who plan to take an investigational * History of alcohol or drug abuse in the six month period prior to Visit 1, or who plan to take an investigational drug for another study during this study. * History of noncompliance to medical regimes or who are considered potentially unreliable. * Pituitary radiotherapy within the last 1 year prior to study entry. * Unable to complete the entire study for any reason.