Weight Loss Study for Patients With Obesity Due to Craniopharyngioma or Other Brain Tumor

Phase 2

Completed

Brief Summary: The purpose of this study is to determine whether exenatide can cause weight loss in patients with a history of craniopharyngioma or other brain lesion.

Detailed Description: Hypothalamic obesity occurs in up to 60% of patients with tumors in the hypothalamic region, most commonly craniopharyngiomas. Hypothalamic dysfunction can be due to tumor infiltration and as a consequence of surgery or radiation therapy. Survivors who develop obesity have greater morbidity and mortality than normal weight survivors. Prevention and treatment of obesity in this population is vital in order to decrease the morbidity and mortality from diabetes, stroke and myocardial infarction.

Exenatide (Byetta®) is a GLP-1 homologue that was FDA approved for treatment of type 2 diabetes in 2005. It also decreases the rate of gastric emptying and increases satiety and has been shown to cause weight loss in some people. Exenatide may improve insulin sensitivity and satiety in patients with hypothalamic obesity but without the risks of bariatric surgery. The investigators hypothesize that treatment with exenatide will lead to weight loss in patients with hypothalamic obesity.

Recruitment & Eligibility

Inclusion Criteria

Age 18 to 40 years old
History of craniopharyngioma or other lesion in the hypothalamic region
Greater than 6 months post-treatment, including chemotherapy, surgery or radiation
BMI >30 mg/m2
Females must be post-menopausal, surgically sterile or using effective birth control for at least 12 weeks

Exclusion Criteria

HgbA1C >7%
Use of diabetes medications other than metformin in the past 12 weeks, including exenatide
Use of weight loss drugs or initiation of a weight loss program in past 3 months
Impaired renal function or history of kidney transplant
History of gall stones (unless s/p cholecystectomy), pancreatitis or alcoholism
Personal or family history of medullary carcinoma of the thyroid or MEN type 2
History of gastroparesis or other gastric motility problems as exenatide decreases gastric motility
History of allergic reaction to exenatide or other medication components
Other significant comorbidities other than pituitary deficiencies
Currently prescribed warfarin (exenatide may alter warfarin metabolism)
Pregnant or lactating females
History of severe hypoglycemia (BG <60 and requiring assistance from another person)

Arm && Interventions

Group	Intervention	Description
Exenatide	Exenatide	All patients received exenatide 10mcg BID x 50 weeks

Primary Outcome Measures

Name	Time	Method
Body Weight (kg)	baseline, 50 weeks	Change in body weight from baseline to end of study

Secondary Outcome Measures

Name	Time	Method
Visual Analogue Scales for Post-meal Satiety	baseline, 50 weeks	Change in visual analogue scales scores from baseline to 50 weeks. Higher score indicates greater satiety (minimum 0, maximum 100).
Resting Energy Expenditure (Kcals Per Day)	baseline, 50 weeks	Change in resting energy expenditure from baseline to 50 weeks
Insulin Secretion (Area Under the Curve)	baseline, 50 weeks	Change in insulin secretion from baseline
Gastric Emptying Rate (13C-octanoic Acid Isotope Excretion Half Life)	baseline, 50 weeks	Change in the isotope excretion half life during a gastric emptying test at baseline and at 50 weeks