Seres Therapeutics Inc. said the U.S. Food and Drug Administration granted orphan drug designation to its SER-287 microbiome therapeutic candidate for treating pediatric patients with ulcerative colitis.

The designation follows a review of data from the phase 1b study evaluating SER-287 for ulcerative colitis treatment. The company expects results from the trial in early 2018.

Ulcerative colitis is a serious chronic condition affecting about 700,000 people in the U.S. The disease results in inflammation of the colon and rectum and may lead to colon removal.