A Study to Evaluate the Safety and Efficacy of RM-131 Administered to Patients With Vomiting Symptoms and Moderate to Severe Diabetic Gastroparesis

Inclusion Criteria:

- T1DM or T2DM with stable glycemic control and HbA1c ≤11% at screening.

- DG, 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 (Visits 1-2).

- At least 2 vomiting episodes during the ~2 weeks prior to the first screening visit
(Visit 1), as ascertained by patient history.

- Delayed GE confirmed at screening by abnormal Gastric Emptying Breath Test (GEBT),
defined as GE 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.

- Patients with 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.