Seres Therapeutics (NASDAQ: MCRB) slashes 25% of workforce to extend cash runway

Rhea-AI Filing Summary

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.

Positive

• None.

Negative

• Significant restructuring and financial strain: Seres is reducing its workforce by approximately 25% and explicitly cites the need for additional funding and its ability to continue as a going concern, indicating meaningful financial pressure despite extending its cash runway only into the second quarter of 2026.

Insights

Biotech equity analyst

Seres cuts 25% of staff to extend cash into Q2 2026 amid going-concern risks.

Seres Therapeutics is implementing a sizable workforce reduction of about 25% to lower operating expenses. The company expects cash restructuring charges of $1.0 to $1.4 million in Q4 2025, mainly for severance, in exchange for ongoing savings that management believes will stretch its cash runway into Q2 2026.

Management explicitly highlights key risks: the need for additional funding, the ability to continue as a going concern, a history of operating losses, and the possibility that the cost savings plan does not achieve its intended benefits. These statements underscore that liquidity and business sustainability remain central issues.

From an investor perspective, this move signals a defensive restructuring to conserve cash rather than growth-driven hiring. Actual impact will depend on whether the reduced organization can still execute on strategic priorities and whether future financing or business developments alleviate the going-concern and funding risks flagged here.

8-K Event Classification

Item 8.01 — Other Events

1 item

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Understanding 8-K Material Events →

false 0001609809 0001609809 2025-09-23 2025-09-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 23, 2025

SERES THERAPEUTICS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware		001-37465		27-4326290
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

101 Cambridgepark Drive
Cambridge, MA		02140
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (617) 945-9626

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common stock, par value $0.001 per share		MCRB		The Nasdaq Stock Market LLC (Nasdaq Global Select Market)

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01. Other Events.

On September 23, 2025, Seres Therapeutics, Inc. (the “Company”) announced actions to reduce operating costs in order to extend its cash runway to provide additional opportunities to advance its strategic priorities.

In this announcement, the Company reported that it was reducing its workforce by approximately 25% (including reductions that were effective in August 2025), and the workforce reduction is expected to result in cash charges of approximately $1.0 to $1.4 million, primarily related to severance costs, to be paid in the fourth quarter of 2025. As a result of the anticipated cost savings arising from these previously announced initiatives, and based on current operating plans, the Company expects to extend its cash runway into the second quarter of 2026. The foregoing estimates are based upon current assumptions and expectations but are subject to known and unknown risks and uncertainties. Accordingly, the Company may not be able to fully realize the cost savings and benefits initially anticipated from such actions, and the expected costs may be greater than expected.

Forward-Looking Statements

This Current Report on Form 8-K (this “Current Report”) contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this Current Report that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding cost saving initiatives, including anticipated workforce reductions, restructuring charges, cash savings, operating plans and our cash runway, and the timing of any of the foregoing. These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause the Company’s actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: (1) our need for additional funding; (2) our ability to continue as a going concern; (3) we have incurred significant losses, are not currently profitable and may never become profitable; (4) our history of operating losses; (5) our cost savings initiative may not be successful, and may not have its anticipated benefits; (6) our ability to manage our recent CEO transition, to retain key personnel and to manage our growth; and the other important factors discussed under the caption “Risk Factors” in the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 6, 2025, and the Company’s other reports filed with the Securities and Exchange Commission could cause actual results to differ materially from those indicated by the forward-looking statements made in this Current Report. Any such forward-looking statements represent management’s estimates as of the date of this Current Report. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause the Company’s views to change. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date of this Current Report.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

				SERES THERAPEUTICS, INC.
Date: October 3, 2025				By:		/s/ Thomas J. DesRosier
				Name:		Thomas J. DesRosier
				Title:		Co-Chief Executive Officer, Co-President, Executive Vice President, Chief Legal Officer and Secretary

FAQ

Why is Seres Therapeutics (MCRB) reducing its workforce?

Seres Therapeutics is cutting its workforce by approximately 25% to reduce operating costs and extend its cash runway, aiming to create additional room to advance its strategic priorities.

How much will the Seres Therapeutics (MCRB) restructuring cost?

The workforce reduction is expected to result in cash charges of approximately $1.0 to $1.4 million, primarily related to severance costs, to be paid in the fourth quarter of 2025.

How does the cost-saving plan affect Seres Therapeutics' cash runway?

Based on anticipated cost savings and current operating plans, Seres Therapeutics expects the initiatives to extend its cash runway into the second quarter of 2026.

What risks does Seres Therapeutics (MCRB) highlight around its cost savings plan?

The company notes risks including its need for additional funding, its ability to continue as a going concern, its history of operating losses, and the possibility that the cost savings initiative may not achieve the anticipated benefits.

When will Seres Therapeutics (MCRB) pay the restructuring charges?

Seres Therapeutics expects to pay the approximately $1.0 to $1.4 million in cash charges related to the workforce reduction in the fourth quarter of 2025.

Does Seres Therapeutics expect its cost savings initiative to be successful?

The company states that its expectations are based on current assumptions and are subject to risks and uncertainties, and it may not fully realize the cost savings and benefits initially anticipated.