Aprepitant is an FDA-approved medication for the treatment of nausea following chemotherapy or surgery. Aprepitant is also used by some doctors to reduce nausea and vomiting in patients with gastroparesis, although the drug is not approved for this use. The Aprepitant for the Relief of Nausea in Patients with Chronic Nausea and Vomiting of Presumed Gastric Origin (APRON) study is a multicenter, randomized, placebo-controlled clinical trial designed to test the safety and efficacy of aprepitant in reducing symptoms among patients with gastroparesis.

Patients at least 18 years of age who have experienced symptoms of chronic nausea and vomiting related to gastroparesis for at least 6 months are eligible for the study. Participants are randomized to treatment with either aprepitant (125 mg/day) or placebo for 4 weeks. Nausea symptoms are measured daily on a 0 to 100 mm visual analog scale (VAS) for one week at baseline and for four weeks after randomization. The primary outcome measure is improvement in VAS scores from baseline to through the course of treatment, as defined by a 25 mm or more reduction in mean VAS or attaining a mean VAS during the treatment period of < 25 mm. Improvement in other gastrointestinal symptoms, including symptoms of fullness, hunger, bloating, and abdominal pain, will be measured using the Gastroparesis Cardinal Symptom Index Daily Diary (GCSIDD), an overall relief of symptom questionnaire, and patient perception of improvement. Safety will be determined through satiety tests, electrogastrography for measuring of EGG dysrhythmias, and monitoring of side effects.

The primary objective of the APRON study is to test the efficacy of aprepitant as compared to placebo in improving the symptoms of chronic nausea and vomiting of presumed gastric origin. In addition, the study aims to investigate the how aprepitant affects the symptoms of fullness, hunger, bloating, and abdominal pain, as well as to assess safety.

The primary outcome measure is improvement in VAS scores from baseline to through the course of treatment, as defined by a 25 mm or more reduction in mean VAS or attaining a mean VAS during the treatment period of < 25 mm. Secondary outcome measures include improvement in other gastrointestinal symptoms, as measured by Gastroparesis Cardinal Symptom Index Daily Diary (GCSIDD), an overall relief of symptom questionnaire, and patient perception of improvement. Safety will be assessed through satiety tests, electrogastrography for measuring of EGG dysrhythmias, and monitoring of side effects.

Patients of at least 18 years of age who met the following criteria were eligible for enrollment:

• Gastric emptying scintigraphy within 2 years of registration
• Normal upper endoscopy or upper GI series within 2 years of registration
• Symptoms of chronic nausea or vomiting compatible with gastroparesis or other functional gastric disorder for at least 6 months (does not have to be contiguous) prior to registration with a Gastroparesis Cardinal Symptom Index score of ≥ 21
• Significant nausea defined with a VAS score of ≥ 25 mm on a 0 to 100 mm scale