Pasireotide in Hyperinsulinemic Hypoglycemia

Inclusion criteria: 1. Male or female patients aged 18 to 70 years old 2. Patients with hyperinsulinemic hypoglycemia due to either congenital hyperinsulinemic hypoglycemia or insulinoma, as determined by an endocrinologist 3. If no prior diagnosis of either insulinoma or congenital hyperinsulinemic hypoglycemia by an endocrinologist, the participant must meet the following criteria: * A history of symptoms of hypoglycemia, (with or without a blood glucose \<50mg/dL at time of symptoms) * Improvement of symptoms with ingestion of carbohydrates * At least one documented blood glucose \<50mg/dL with concomitant insulin \>3 mmol/L and c-peptide \>0.2nmol/L, with a negative sulfonylurea screen * At least 1 episode of glucose \<50mg/dL in the last year 4. Written informed consent obtained prior to treatment to be consistent with local regulatory requirements 5. No evidence of significant liver disease: * Serum total bilirubin \< 2 x ULN * INR \< 1.3 unless on anticoagulation * ALT and AST \< 2 x ULN * Alkaline phosphatase \< 2.5 x ULN 6. Patients receiving anti-hypoglycemic treatment are eligible 7. Patients who are treatment naïve, or those who were previously, but not currently, treated with anti-hypoglycemic therapy are also eligible 8. Patients with insulinoma who are operative candidates are eligible if surgery is not emergently needed, and study participation would not delay the timing of a surgical intervention Exclusion criteria: 1. Age \<18, age \>70 (for both insulinoma and congenital hyperinsulinism) 2. Known hypersensitivity to somatostatin or analogues 3. Diabetic patients with poor glycemic control as evidenced by HbA1c \>8% 4. Patients who are hypothyroid and not on adequate replacement therapy 5. Patients with symptomatic cholelithiasis and acute or chronic pancreatitis 6. QTcF at screening \> 450 msec in males and QTcF \> 460 msec in females 7. Hypokalaemia, hypomagnesaemia, family history of long QT syndrome or concomitant medications with known risk of Torsades de pointes (TdP) 8. Patients who have congestive heart failure (NYHA Class III or IV), unstable angina, sustained ventricular tachycardia, clinically significant bradycardia, advanced heart block, history of acute MI less than one year prior to study entry or clinically significant impairment in cardiovascular function 9. Severe non-malignant medical illness that may be jeopardized by treatment with a single dose of pasireotide 10. History of another primary malignancy, with the exception of locally excised non-melanoma skin cancer and carcinoma in situ of uterine cervix unless there is no evidence of disease in the last year 11. Patients with serum creatinine \>2.0 X ULN 12. Patients with WBC \<3 X 109/L; Hb 90% \< LLN; PLT \<100 X 109/L 13. Patients with the presence of active or suspected acute or chronic uncontrolled infection 14. Patients who have undergone major surgery/surgical therapy for any cause within 4 weeks prior screening 15. History of unexplained syncope or family history of idiopathic sudden death 16. Sexually active males unless they use a condom during intercourse while taking drug and for 3 months following last dose of pasireotide and should not father a child in this period. A condom is required to be used also by vasectomized men in order to prevent delivery of the drug via seminal fluid. 17. Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test 18. Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using highly effective methods of contraception during dosing and 30 days following last dose of pasireotide.