Seres Therapeutics (MCRB) Registration filing summary

Company overview and business model

• Focuses on developing live biotherapeutic products (LBPs) for oncology and inflammatory/immune diseases, leveraging human microbiome data to address unmet medical needs in medically compromised populations.

• Successfully developed and gained FDA approval for VOWST, an orally administered microbiome biotherapeutic, which was sold to Nestlé affiliates in September 2024.

• Pipeline includes SER-155, SER-603, SER-428, SER-147, and additional early-stage candidates.

Financial performance and metrics

• Aggregate market value of outstanding common stock held by non-affiliates was $63,154,255.12 as of August 11, 2026, with 10,044,781 shares outstanding and 7,758,508 held by non-affiliates.

• Net tangible book value as of June 30, 2026 was $34.5 million ($3.51 per share); after the offering, as adjusted, would be $131.7 million ($4.20 per share).

• New investors in the offering would experience immediate dilution of $0.44 per share.

Use of proceeds and capital allocation

• Net proceeds from the offering will be used to advance product candidate development and for general corporate and working capital purposes.

• Pending use, proceeds will be invested in short-term, interest-bearing, investment-grade securities or certificates of deposit.