Safety, PK and Efficacy of PCS12852 on Gastric Emptying Rate in Patients With Moderate to Severe Gastroparesis

Inclusion Criteria: * Has documented diagnosis of moderate to severe DG or IG according to the ANMS GCSI-DD score during the Screening period (score of \>2 on average of the screening days). * Moderate to severe delay in gastric emptying rate as measured by the GEBT at Screening defined as GE half-time (t1/2) ≥ the 80th percentile of normative data as determined by Cairn Diagnostics. * Male or female patients 18 to 80 years of age, inclusive, at baseline. * Has continuous moderate to severe symptoms for gastroparesis (that is, chronic postprandial fullness, abdominal pain, postprandial nausea, vomiting, loss of appetite and/or early satiety) as assessed by the investigator for at least the past 3 months. * Has hemoglobin A1c (BbA1c) \< 11%. * Has Body Mass Index range between 18-40. * Women of childbearing potential must use one of the following acceptable methods of contraception throughout the study (1 month prior to Screening through 1 month after last dose of study medication): oral contraceptive medication, IUD, hormonal implants, injectable contraceptive methods, double-barrier methods, or tubal ligation. * Male patients must be willing to use acceptable contraceptive measures such as vasectomy or double-barrier method and refrain from sexual activity with any female who is pregnant or lactating. Female partners of study participants are asked to use acceptable methods of contraception. Exclusion Criteria: * Has acute, severe gastroenteritis and pronounced dehydratio…