This is a multicenter, randomized, double-blind, incomplete block, three period fixed sequence crossover, multicenter, placebo-controlled study. The study will assess three oral doses of velusetrag (5 mg, 15 mg, and/or 30 mg) or placebo, administered once daily in three periods of 1-week duration each, with a 1-week washout period between treatment periods, in subjects with diabetic or idiopathic gastroparesis.

Study 0093 will evaluate the effect of velusetrag in subjects with diabetic or idiopathic gastroparesis by assessing changes in gastric emptying.

Inclusion Criteria:

• Symptoms of gastroparesis (e.g., nausea, early satiety, fullness, bloating, upper abdominal pain, retching or vomiting) for at least 3 months prior to Screening
• Body Mass Index (BMI) between 18 and 35 kg/m2, inclusive
• Gastroparesis Cardinal Symptom Index (GCSI-2W) composite score ≥2 and ≤4 at Screening
• Delayed gastric emptying, defined as a gastric emptying half-time (GE t1/2) > 160 minutes as determined by [13C]-octanoate breath test, at Screening
• Upper gastrointestinal (UGI) obstruction ruled out by endoscopy or other imaging reasonably proximal to the diagnosis of gastroparesis

Exclusion Criteria:

• Acute severe gastroenteritis within 2 weeks prior to Screening
• History of gastric outlet obstruction
• Prior history of gastric surgery, including but not limited to gastrectomy, gastric bypass, gastric banding, pyloroplasty, vagotomy, or fundoplication
• Recurrent vomiting, defined as vomiting more than 2 days per week
• Hospitalization for treatment of gastroparesis or complications of diabetes within 4 weeks prior to Screening
• Presence of thyroid dysfunction not controlled by treatment. Subjects with abnormal thyroid stimulating hormone (TSH), hypothyroidism, or hyperthyroidism at Screening
• If Type 1 or Type 2 diabetic, a glycosylated hemoglobin (HbA1c) level >10% or a glucose > 250 mg/dL at Screening