CLIN1001-002 was a Phase 1b, randomized, double-blind, placebo controlled study to determine the safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of larazotide acetate in subjects with celiac disease subjects. Study subjects were randomized (2:1) to receive single oral doses of larazotide acetate 12 mg or matching placebo once daily for 3 days. Subjects received a single-blinded gluten challenge (5 mg amygluten) on Day 2. Intestinal permeability was measured each day following dosing. Intestinal permeability was measured by administration of an oral sucrose, lactulose and mannitol solution followed by a 6-hour urine collection. Serial blood samples were collected for pharmacokinetic determinations at baseline and 2 and 3 hours post dose; for zonulin determinations at baseline (prior to first dose) and 3 hours post dose; and for cytokine determination at baseline and 3 hours post dose (Days 2 and 3 only) and on Day 7. Sucrose, lactulose, mannitol, zonulin and larazotide acetate concentrations were determined by validated analytical methods.