A Scintigraphy Study in Adults With Diabetic Gastroparesis

Inclusion Criteria: * Male and female patients 18 to 70 years old, inclusive. * Type 1 or Type 2 diabetes mellitus, according to American Diabetes Association criteria * Current diagnosis of diabetic gastroparesis. * Body Mass Index (BMI) between 18 and 40 kg/m2, inclusive. * Glycosylated hemoglobin level \<11% at Screening. * Willing to abstain from tobacco or nicotine-containing product use after midnight on the day of the DAS test and throughout the time that gastric emptying is being imaged. * Willing to abstain from grapefruit, grapefruit products, star fruit, star fruit products, and Seville oranges from 72 hours prior to the Randomization Visit until end of study. Exclusion Criteria: * History of, or current, clinically significant arrhythmias as judged by the Investigator, including ventricular tachycardia, ventricular fibrillation, atrial fibrillation, and Torsades de Pointes. Patients with minor forms of ectopy (eg, premature atrial contractions) are not necessarily excluded. * Clinically significant bradycardia with a resting heart rate under 50 beats per minute, sinus node dysfunction, or heart block. * Prolonged heart rate-corrected QT interval using Fridericia's formula (QTcF) (QTcF \>450 msec for males or QTcF \>470 msec for females) based on the average of triplicate ECGs. * A personal or family history of long QT syndrome, Torsades de pointes, or other complex ventricular arrhythmias or family history of sudden death. * Evidence (based on Screening or Baseline assessments) or history of clinically significant immunologic, hematologic, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease (including drug allergies); surgical conditions; cancer (with the exception of basal or squamous cell carcinoma of the skin and cancer that resolved or has been in remission for \>5 years prior to the Screening Visit); or any condition that, in the Investigator's opinion, might significantly interfere with the absorption, distribution, metabolism, or excretion of the study drug. * History of prolactin-releasing pituitary tumor (ie, prolactinoma). * Allergic to egg or intolerant to gluten. * History of alcoholism or drug abuse within 2 years prior to dosing as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition. * Known or suspected gastric outlet obstruction (eg, peptic stricture) or other gastrointestinal mechanical obstruction. * Known history or current diagnosis of intestinal malabsorption or pancreatic exocrine disease. * History or presence of any medical condition or psychiatric disease, which, in the opinion of the Investigator, could interfere with the conduct of the study or would put the patient at unacceptable risk. * Judged by the Investigator, after reviewing medical and psychiatric history, physical examination, and laboratory evaluation, to be unsuitable for any other reason that may either place the patient at increased risk during participation or interfere with the interpretation of the study outcomes.