Inclusion Criteria

• Type 1 or type 2 diabetes with stable glycemic control and blood A1c ≤11% at screening
• Diabetic Gastroparesis, defined as at least a 3-month history of symptoms suggestive of gastroparesis on an ongoing basis (e.g., vomiting, nausea, early satiety, bloating, or epigastric or abdominal pain)
• Gastroparesis Cardinal Symptom Index Daily Diary (GCSI-DD) score ≥ 2.6 at least once during the screening period
• At least 2 vomiting episodes during the ~2 weeks prior to the first screening visit  as ascertained by patient history.
• Delayed gastric emptying confirmed at screening by abnormal Gastric Emptying Breath Test (GEBT), defined as gastric emptying half-time (t1/2) ≥ 79 minutes (the 80th percentile of normative data)
  • At least 50% of patients enrolled will have a t1/2 ≥ 97 minutes (i.e., the 95th percentile)
• Stable concomitant medications, defined as no changes in regimen for at least 2 weeks prior to visit 2
  • daily adjustments of insulin doses are permitted
• No use of metoclopramide, erythromycin, domperidone, or other GI motility agents, or anti-emetics for at least 2 weeks prior to visit 2, and willingness to remain off these medications (except as used as part of protocol-specific rescue medication) during the course of the clinical trial
• Body mass index >18 kg/m2
• If female, has a negative serum or urine pregnancy test and is not lactating
• For females able to bear children, a hormonal (i.e., oral, implantable, or injectable) and single-barrier method, or a double-barrier method of birth control must be used throughout the study
• Female patients unable to bear children must have this documented in the electronic case report form (eCRF) (i.e., tubal ligation, hysterectomy, or post-menopausal [defined as a minimum of 1 year since the last menstrual period])
  • Post-menopausal status will be confirmed by measurement of follicle stimulating hormone (FSH)
• Able to provide written informed consent prior to any study procedures and willing and able to comply with study procedures
• Additional inclusion criteria for randomization after the 2-week single-blind placebo run-in period
  • Compliance with the completion of the DGSSD and study drug injections, defined as approximately 80% diary completions and approximately 80% administration of injections, during the 2-week single-blind placebo run-in period
  • For those patients whose compliance is measured to be <80%, the final decision to randomize a patient will be made by the Investigator and the Sponsor (or designee)
  • At least one vomiting episode at any time during the 2-week single-blind placebo run-in period, as recorded in the DGSSD

Exclusion Criteria

• Currently receiving parenteral feeding or presence of a nasogastric or other enteral tube [e.g., PEG (percutaneous endoscopic gastrostomy) tube] for feeding or decompression
• History of gastric surgery such as fundoplication, gastrectomy, gastric pacemaker placement, vagotomy, or bariatric procedure
  • A history of diagnostic endoscopy is not exclusionary
• History of pyloric injection of botulinum toxin within 6 months of screening
• Clinical suspicion of upper gastrointestinal (GI) obstruction (e.g., peptic stricture) must have been evaluated per standard of care and obstruction ruled out before screening
• Currently taking opiates, or expecting to use opiates during the course of the clinical trial
• Currently taking GLP-1 agonists, SGLT2 inhibitors or pramlintide
• Allergic or intolerant of egg, wheat, milk, or algae, as these are components of the GEBT study meal. (Gluten-free crackers can be provided)
• History of anorexia nervosa, binge-eating, or bulimia within 5 years of screening
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 2 × upper limit of normal (ULN) at visit 1
• History of intestinal malabsorption or pancreatic exocrine disease
• Requires hemodialysis or has end-stage renal disease
• History of human immunodeficiency virus (HIV) infection
• Clinically significant neurologic or psychiatric disorders that are likely to impact compliance with protocol requirements
• Poor venous access or inability to tolerate venipuncture
• Participation in a clinical study within the 30 days prior to dosing in the present study
• Any other reason that, in the Investigator's opinion, would confound proper interpretation of the study or expose a patient to unacceptable risk, including renal, hepatic or cardiopulmonary disease, or significant acute electrocardiogram (ECG) abnormalities