Seres Therapeutics (MCRB) Status update summary

Leadership and Organizational Updates

• Richard N. Kender appointed as Executive Chair and Interim CEO, bringing over 35 years of biopharma experience, including senior roles at Merck & Co.

• Previous co-CEOs continue as Chief Legal Officer and Chief Financial Officer, ensuring leadership continuity.

• Matthew Henn, Ph.D., becomes President in addition to Chief Scientific Officer; Kelly Brady, M.S., promoted to Chief Operating Officer.

• Recent management transitions aim to leverage deep biopharma experience and drive the mission in live biotherapeutics.

Strategic Focus and Pipeline Developments

• Strategy centers on advancing live biotherapeutic programs with strong scientific rationale and commercial potential, focusing on inflammatory and immune diseases, especially IBD and irEC.

• SER-155 is Phase 2 ready for allo-HSCT patients, with funding efforts ongoing and phase II preparations paused pending funding but ready to resume.

• SER-155 is being evaluated in a fully enrolled investigator-sponsored trial for irEC, with data expected in Q2 2026.

• SER-603, a preclinical candidate for IBD, is progressing through IND-enabling activities and is designed as a non-immunosuppressive treatment option.

• Collaborations with Memorial Sloan Kettering and CARB-X support clinical and formulation advancements, including development of an oral liquid LBP formulation based on SER-155 strains.

Financial and Operational Update

• Cash and cash equivalents stood at $45.8 million as of December 31, 2025, including $12.2 million raised in Q4 2025.

• Operating costs have been reduced, including workforce reductions, to extend the cash runway.

• Current cash is expected to fund operations through Q3 2026, with ongoing efforts to secure additional funding and further opportunities to extend runway being evaluated.

• Future financial results and business updates will be communicated via press release; earnings calls will be discontinued.