Seres Posts Interim Microbiome Data Analysis From Failed Ulcerative Colitis Study

Seres Therapeutics Inc (NASDAQ: MCRB) announced preliminary microbiome data analyses from the Phase 2b ECO-RESET study of SER-287 in patients with mild-to-moderate ulcerative colitis (UC). 

• In July, the Company posted the topline data readout, which noted that the SER-287 Phase 2b study did not achieve its primary endpoints. 
• The Company continues to conduct analyses on its SER-287 and SER-301 UC clinical-stage programs to inform next steps for further development.
• Engraftment of SER-287 bacteria was statistically significant in patients receiving SER-287 versus placebo.
• The magnitude and kinetics of engraftment were comparable to Seres' Phase 1b study. However, unlike the Phase 1b study, anticipated changes in disease-relevant metabolites post-administration with SER-287 in the Phase 2b study were not observed.
• "Our SER-287 Phase 2b data suggests that there may be an opportunity to utilize biomarker-based patient selection in our future UC development efforts," said Eric Shaff, Chief Executive Officer at Seres.
• Price Action: MCRB shares are down 3.55% at $8.42 during the market session on the last check Thursday.