Seres Therapeutics : Phase 2b Study On Ulcerative Colitis Fails To Meet Main Goal; Stock Plunges

(RTTNews) - Seres Therapeutics Inc. (MCRB) said that a phase 2b ECO-RESET study, which evaluated SER-287 in patients with mild-to-moderate ulcerative colitis, did not meet its primary endpoint of improving clinical remission rates compared to placebo. Both dosing regimens of SER-287 were generally well tolerated.

In Thursday pre-market trading, MCRB was trading at $13.50 down $7.33 or 35.19%.

The company has decided to close the open label and maintenance portions of the study, due to lack of a clinical efficacy signal identified in the study.

The company noted that the efficacy results in the trial did not meet the pre-defined threshold. But it believes the data-rich study, including microbiome analyses expected in the second half of 2021, will provide valuable insights to inform continued development of its pipeline, including SER-301, next generation investigational candidate for ulcerative colitis.

The company said it continues to advance its SER-301 program currently in a Phase 1b study that is testing the hypothesis that engraftment of drug product species modulates microbe-associated metabolites to reduce intestinal inflammation and improve epithelial barrier integrity in adults with mild-to-moderate UC. The Phase 1b is currently enrolling in Australia and New Zealand.