Welcome to our dedicated page for Seres Therapeutics SEC filings (Ticker: MCRB), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
The Seres Therapeutics, Inc. (MCRB) SEC filings page on Stock Titan provides access to the company’s official disclosures as filed with the U.S. Securities and Exchange Commission. These documents include Form 8-K current reports, which Seres uses to announce quarterly financial results, operational updates, leadership changes, cost-reduction actions, and other material events.
For a clinical-stage live biotherapeutics company like Seres, SEC filings are a primary source of information on the status of its programs and financial position. In recent 8-K filings, the company has reported results and updates related to its lead investigational candidate SER-155, including descriptions of Phase 1b data in adults undergoing allogeneic hematopoietic stem cell transplant (allo-HSCT), regulatory designations such as Breakthrough Therapy and Fast Track, and ongoing interactions with the U.S. Food and Drug Administration regarding a planned Phase 2 study design.
Filings also discuss the company’s classification of historical VOWST™ operating results as discontinued operations following the sale of that asset to Nestlé Health Science, as well as the provision of manufacturing services under a Transition Services Agreement. Additional disclosures cover cash runway expectations, workforce reductions, and business development efforts aimed at securing capital or strategic partnerships to advance SER-155 and other live biotherapeutic candidates.
On Stock Titan, these SEC filings are complemented by AI-powered summaries that highlight key points from lengthy documents, helping readers quickly understand topics such as trial plans, risk factor discussions, and material corporate actions. Users can review 8-Ks and other filings in real time as they are posted to EDGAR, and use AI-generated insights to interpret how Seres’ regulatory and financial disclosures relate to its live biotherapeutics pipeline and overall strategy.
Seres Therapeutics (MCRB) furnished an update via Form 8-K announcing financial results for the quarter ended September 30, 2025 and providing operational updates. The company also shared an updated corporate presentation for investors.
The press release is furnished as Exhibit 99.1 and the investor slide deck as Exhibit 99.2. Consistent with Items 2.02 and 7.01, these materials are furnished, not filed, and are not subject to Section 18 liabilities or incorporation by reference except as expressly stated.
Seres Therapeutics, Inc. is cutting its workforce by approximately 25%, including reductions that took effect in August 2025, as part of a plan to reduce operating costs and extend its available cash. The company expects to incur cash charges of about $1.0 to $1.4 million in the fourth quarter of 2025, primarily for severance.
Based on these cost-saving measures and current operating plans, Seres expects its cash runway to extend into the second quarter of 2026. The company cautions that these expectations rely on current assumptions and are subject to significant risks, including its need for additional funding, its ability to continue as a going concern, its history of losses, and the possibility that the cost savings initiative does not deliver the anticipated benefits.
Matthew R. Henn, Chief Scientific Officer and EVP of Seres Therapeutics (MCRB), was granted 3,998 restricted stock units (RSUs) on 09/26/2025. Each RSU converts to one share of common stock and the award was reported as acquired at a $0 price. The RSUs are scheduled to vest in a single installment on 11/15/2025, subject to satisfaction of the award agreement terms, and the RSUs have no expiration date. Following the reported transaction the filing shows beneficial ownership of 3,998 shares reported as direct.
Eric D. Shaff, a director of Seres Therapeutics (MCRB), received and reported the settlement of restricted stock units and a small sale of common stock under a 10b5-1 plan. On 08/15/2025 he had two non-derivative acquisitions: 391 and 333 shares issued on settlement of restricted stock units, increasing his beneficial ownership to 10,493 and 10,826 shares respectively. On 08/18/2025 he sold 217 shares at $16.65 each, which the form states were executed under a Rule 10b5-1 instruction adopted to cover taxes related to RSU vesting. The RSUs vest in scheduled installments (25% earlier vesting followed by quarterly vesting) and have no expiration date.
Insider transactions at Seres Therapeutics (MCRB): Thomas J. DesRosier, a senior executive identified as Chief Legal Officer, EVP, Co‑CEO and Co‑President, reported restricted stock unit vesting and a small sale under a preexisting Rule 10b5‑1 plan. On 08/15/2025 DesRosier had 133 and 111 restricted stock units settle into common shares (total 244 shares) and beneficially owned 7,420 and 7,531 shares respectively after those settlements. On 08/18/2025 he sold 76 shares at $16.65 per share pursuant to the 10b5‑1 instruction to cover taxes related to vesting. The filings state the RSUs vest in scheduled quarterly installments and have no expiration.
Matthew R. Henn, Chief Scientific Officer and EVP of Seres Therapeutics (MCRB), reported equity changes on a Form 4. Restricted stock units vested and settled on 08/15/2025: 141 RSUs and 97 RSUs were reported as acquired/settled, each representing one share. A subsequent sale on 08/18/2025 disposed of 73 shares at $16.65 per share under a Rule 10b5-1 plan adopted April 13, 2023 to cover taxes related to vesting. Following these transactions the filing shows 4,548 shares beneficially owned and remaining RSU balances of 844 and 976 as reported.
Teresa L. Young, EVP, Chief Commercial & Strategy Officer of Seres Therapeutics, Inc. (Ticker: MCRB), reported vesting and settlement of restricted stock units and a small sale of common stock in August 2025. On 08/15/2025 two tranches of restricted stock units were reported (133 and 97 RSUs) that represent contingent rights to receive shares; the filings show post-transaction beneficial ownership figures of 5,177 and 5,274 shares respectively. On 08/18/2025 the reporting person sold 59 shares at $16.65, executed under a Rule 10b5-1 instruction adopted March 5, 2023, described as intended solely to cover taxes relating to RSU vesting. The Form 4 is signed by an attorney-in-fact on 08/19/2025.