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.
Seres Therapeutics, Inc. filings document the disclosure record of a Nasdaq-listed biotechnology company focused on live biotherapeutic and microbiome-based therapeutic programs. Its Form 8-K reports furnish quarterly and annual financial results, operational updates, Regulation FD corporate presentations, and material-event disclosures involving pipeline priorities, clinical and regulatory matters, capital allocation, cost-reduction actions, and financing or partnership activity.
The company’s proxy materials cover annual meeting mechanics, stockholder voting, board governance, executive compensation, and equity-award information. SEC filings also identify Seres’ common stock registered under the Exchange Act and traded on the Nasdaq Global Select Market under the symbol MCRB.
Seres Therapeutics reported fourth quarter and full year 2025 results and outlined its microbiome pipeline strategy. For 2025, the company generated $0.8 million in grant revenue and recorded $5.7 million in net income from continuing operations, driven largely by an $80.7 million gain on the sale of its VOWST business and lower operating expenses of $94.8 million versus $121.3 million in 2024.
As of December 31, 2025, Seres held $45.8 million in cash and cash equivalents and expects this to fund operations through the third quarter of 2026, while it seeks partnerships and other financing. The company is prioritizing live biotherapeutic programs for inflammatory and immune diseases, including SER-155, which showed a 77% relative risk reduction in bloodstream infections in a Phase 1b allo-HSCT study and is Phase 2 ready, and SER-603 for inflammatory bowel disease. An investigator-sponsored SER-155 trial in immune checkpoint inhibitor–related enterocolitis is fully enrolled, with data expected in the second quarter of 2026.
Seres Therapeutics, Inc. reported that officer Kelly Brady received a grant of stock options for 56,250 shares of common stock on March 4, 2026. The options have an exercise price of $9.13 per share and are held as a direct derivative position.
The option grant vests over time: 25% of the shares vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments after that date. This is a compensation-related award rather than an open-market stock purchase or sale.
Seres Therapeutics insider Brady Kelly has filed an initial ownership report showing existing equity holdings in the company. The filing lists several stock options to purchase Common Stock, including one covering 11,700 shares at an exercise price of 15.6400 per share expiring on February 6, 2035, plus additional options with exercise prices around 22.0000 to 23.0000 per share expiring in 2034. Kelly also holds Restricted Stock Units tied to 358 and 730 shares of Common Stock and directly owns 8,441 shares of Common Stock following the reported positions. The footnotes explain that these options and RSUs vest over time, with 25% already vested and the remainder scheduled to vest in 12 equal quarterly installments after the initial vesting dates.
Kender Richard N reported acquisition or exercise transactions in this Form 4 filing.
Seres Therapeutics, Inc. director and officer Richard N. Kender reported receiving a grant of stock options covering 150,000 shares of common stock. These options give him the right to buy company shares and were reported as a direct beneficial holding.
According to the filing, the option award vests and becomes exercisable in 36 equal monthly installments, providing long-term, incremental equity-based compensation tied to his continued service with the company.
Seres Therapeutics, Inc. disclosed that officer Matthew R. Henn received a grant of stock options covering 75,000 shares of common stock on March 4, 2026. These options give him the right to buy company shares if they vest and are exercised in the future.
According to the vesting schedule, 25% of the option shares will vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments thereafter. This filing reflects an equity-based compensation award rather than an open-market share purchase or sale.
Seres Therapeutics, Inc. reported that officer Marella Thorell received a grant of stock options covering 22,500 shares of the company’s stock. This is classified as a grant or award acquisition, not a market purchase or sale.
According to the vesting terms, 25% of the option shares will vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments after that date. Following this grant, Thorell’s directly held option position from this award totals 22,500 option shares.
DesRosier Thomas reported acquisition or exercise transactions in this Form 4 filing.
Seres Therapeutics, Inc. reported that officer Thomas DesRosier received a grant of stock options covering 22,500 shares of the company’s stock. No cash was paid for this award, which is described as a “Stock Option (right to buy).”
According to the vesting terms, 25% of the option shares will vest on March 2, 2027. The remaining shares will then vest in 12 equal quarterly installments after that date, tying the award to continued service over several years.
Seres Therapeutics announced major leadership changes and new pay packages for top executives. The board appointed director Richard N. Kender as Executive Chair and Interim Chief Executive Officer, effective March 2, 2026. Former Co‑CEOs Thomas J. DesRosier and Marella Thorell stopped serving as Co‑Presidents and Co‑CEOs but remain Chief Legal Officer and Chief Financial Officer.
Chief Scientific Officer Matthew Henn adds the role of President, and Kelly Brady becomes Executive Vice President, Chief Operating Officer. Kender will earn a $520,000 base salary, a 55% target bonus, a $250,000 signing bonus, and options on 200,000 shares. Henn’s salary rises to $505,000 with a 45% target bonus, a $230,000 retention bonus, and options on 100,000 shares. Brady’s salary increases to $475,000 with a 45% target bonus, enhanced severance protections, a $230,000 retention bonus, and options on 75,000 shares. Portions of each option grant depend on stockholder approval of an increase to the 2025 Incentive Award Plan at the 2026 annual meeting.
Seres Therapeutics director Eric D. Shaff reported several equity transactions on February 15, 2026 tied to his restricted stock units (RSUs). He exercised RSU-derived rights for a total of 723 shares of common stock, then sold 259 shares of common stock at $8.47 per share under a pre-arranged Rule 10b5-1 instruction, which the filing states was intended solely to cover taxes from RSU vesting. Following these moves, he directly held 11,577 shares of common stock, while his RSU awards continue to vest in scheduled quarterly installments.
Seres Therapeutics officer Teresa L. Young reported multiple Form 4 transactions involving restricted stock units and common stock. She acquired 231 shares of common stock on February 15, 2026 through exercises of restricted stock units at $0.00 per share, then sold 75 common shares at $8.47 per share. The sale was executed under a pre-arranged Rule 10b5-1 instruction adopted on March 5, 2023 to cover taxes related to vesting of restricted stock units.