Primary Outcome Measures:
- (Safety) AEs to be collected beginning with patient’s first administration of study medication through final study visit
- Clinical chemistry, hematology, and urinalyses to be performed before and after the Treatment Period
- Cardiac safety will be monitored by ECG recordings
- (Efficacy) Primary endpoints for analysis of efficacy are the colonic geometric center (GC) at 24 hours and ascending colon t1/2 values.
Secondary Outcome Measures:
- Secondary transit endpoints will be gastric emptying t1/2, colonic filling at 6 hours, colonic GC at additional time points including 48 hours, and time to first bowel movement after the first dose of medication.
Using a double-blind, randomized, placebo-controlled, parallel group study design, the effects of placebo and two different doses of orally administered MD-1100 Acetate on gastric emptying, small bowel transit and total colonic transit will be compared and evaluated in patients with C-IBS.
After eligibility is confirmed, the patient will return for baseline measurement of colonic transit to ensure that the transit profile is not greater than the mean transit profile of healthy controls in order to avoid a ceiling effect. A patient must have a geometric center of ≤2.65 at 24 hours, or ≤3.0 at 24 hours and ≤3.9 at 48 hours in order to be randomized to a 5-day Treatment Period of study medication. Eligible patients will receive oral study medication for 5 days during which colonic transit will be measured.
Approximately 36 (n=36) patients will be randomized to one of three different treatment groups: placebo (n=12), 100 ug MD-1100 (n=12), or 1000 ug MD-1100 (n=12). All dosing of study medication will be supervised at the Mayo Clinic.
Patients will complete a daily Stool Diary to record bowel habits for 5 consecutive days during the Pretreatment Period and then for the 5 consecutive days of the Treatment PeriodPhysical examinations, vital signs, electrocardiograms, and clinical laboratory tests will be performed throughout the study and adverse events will be recorded for safety evaluation.