Seres Therapeutics Inc.
08/05/2026 | Press release | Distributed by Public on 08/05/2026 05:05
SERES THERAPEUTICS REPORTS SECOND QUARTER 2026 FINANCIAL RESULTS AND PROVIDES BUSINESS UPDATES, INCLUDING FURTHER ACTION TO REDUCE ONGOING FACILITIES COSTS (Form 8-K)
SERES THERAPEUTICS REPORTS SECOND QUARTER 2026 FINANCIAL RESULTS AND PROVIDES BUSINESS UPDATES, INCLUDING FURTHER ACTION TO REDUCE ONGOING FACILITIES COSTS
Recently announced 80% of SER-155 recipients achieved immunosuppressive-free clinical response at day 15 for immune checkpoint inhibitor-related enterocolitis (irEC) in the investigator-sponsored trial (IST) conducted by Memorial Sloan Kettering Cancer Center (MSK)
IST data support SER-155 as a potential treatment for irEC that may allow patients to continue cancer therapy; Company evaluating irEC clinical development strategy in consultation with KOLs
Seres engaging potential partners, seeking capital to advance its SER-155 programs, including for the prevention of bloodstream infections in patients undergoing allo-HCT and those experiencing irEC
Seres announces agreement to exit additional leased space early, further reducing ongoing facility-related cash costs, which follows announcement of balance sheet strengthening and facilities cost reduction transactions in June 2026
CAMBRIDGE, Mass.- August 5, 2026 - Seres Therapeutics, Inc. (Nasdaq: MCRB), (Seres or the Company), a leading live biotherapeutics company, today reported second quarter 2026 financial results and provided business updates.
"We are very pleased with the recent progress at Seres, including the positive topline data from the investigator-sponsored trial of SER-155 in irEC conducted by MSK, announced last month," said Richard Kender, Executive Chairman and Interim Chief Executive Officer of Seres. "The study demonstrated that 80% of participants achieved an immunosuppressive-free clinical response at day 15, and the accompanying pharmacology data reinforced that our live biotherapeutic operated as designed, including by repairing the mucosal epithelial barrier. SER-155 to treat irEC, a frequent and often severe side effect of widely used immune checkpoint inhibitor (ICI) cancer treatment, represents a meaningful therapeutic and commercial opportunity, as many patients who experience irEC are required to halt their ICI therapy and begin immunosuppressive corticosteroid treatment. We are engaging potential partners, including companies with ICI franchises, as we evaluate the clinical development pathway in this indication and consider sources of financing. In parallel, we continue to pursue partnerships and other financing sources to support development of SER-155 in allo-HCT, and to advance our broader inflammatory and immune portfolio, including SER-603 for inflammatory bowel disease."
Marella Thorell, Chief Financial Officer of Seres, added, "Terminating our Sidney Street lease will substantially reduce our future lease obligations and will further lower our ongoing annual fixed costs beginning in 2027. Together with the lease restructuring we announced in June, this transaction reflects our continued focus on rigorous financial discipline, while we maintain the operational infrastructure needed to advance our live biotherapeutic pipeline, including our Phase 2-ready SER-155 program in allo-HCT."
Recent Highlights
SER-155 in immune checkpoint inhibitor-related enterocolitis (irEC)
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In July, Seres announced positive topline results from the IST of SER-155 in irEC (NCT06801067) conducted at MSK. The open-label study evaluated SER-155 in 15 participants with moderate-to-severe (Grade 2-3) irEC who were naïve to immunosuppressive therapy. irEC is among the most frequent and severe immune-related adverse reactions in recipients of ICI therapy and, at the moderate-to-severe grade, affects approximately 25% of ICI recipients in the US. |
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In the study, 12 of 15 participants (80%) achieved an immunosuppressive-free clinical response at day 15, the primary efficacy endpoint, defined as at least a 1-grade improvement in diarrhea symptoms without immunosuppressive therapy. SER-155 was generally well tolerated with no safety concerns identified and no serious adverse events assessed as related to SER-155. |
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Participants in the study were on a wide range of ICI types, including PD-1 inhibitors (Keytruda®, Opdivo®, Zynyz®), PD-L1 inhibitors (Imfinzi®, Bavencio®), CTLA-4 inhibitors (Yervoy®, Imjudo®), LAG-3 inhibitor (Opdualag®), and combinations thereof. The promising study results support continued development of SER-155 to treat irEC and the Company is engaging potential partners, including companies with ICI franchises, as it evaluates next steps for the development of SER-155 in irEC. |
Broader pipeline and portfolio
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SER-155 remains Phase 2 ready for the prevention of bloodstream infections in patients undergoing allogeneic hematopoietic stem cell transplant (allo-HCT) for the treatment of blood cancer. SER-155 has received Breakthrough Therapy and Fast Track designations for this indication. Efforts to secure funding to advance clinical development for this program continue. |
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The Company continues to advance IND-enabling activities for SER-603, in development for inflammatory bowel disease, and is engaging potential collaborators to support the clinical advancement of this program as a mono and/or combination therapy. |
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Seres continues to progress development of SER-428, an investigational oral liquid formulation based on SER-155 strains supported by a grant from CARB-X (Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator), for dosing in patients who cannot take oral capsules. Seres is designing a Phase 1b open-label trial, in collaboration with Dr. Dan Freedberg at Columbia University, to evaluate SER-428 in medical ICU patients at high risk of infection. |
Corporate Updates
Seres completed the below transactions that will collectively strengthen the Company's balance sheet and reduce ongoing annual facility cash costs.
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On July 31, Seres entered into an agreement to terminate the lease for its facility at 200 Sidney Street in Cambridge, MA. This early termination eliminates the Company's remaining obligations under the lease as of December 31, 2026 in exchange for certain consideration and will further significantly reduce ongoing facility-related cash costs beginning in 2027. Additional details regarding the agreement are included in the Company's Report on Form 8-K, which was filed with the Securities and Exchange Commission on August 4, 2026. The accounting for this transaction will be reported in the Company's third quarter 2026 results. |
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In June, Seres restructured the lease for its facility at 101 CambridgePark Drive in Cambridge, MA, reducing its leased space, rental rate and related operating expenses. The restructured 10-year lease is expected to materially reduce the Company's ongoing annual facility-related cash costs and long-term lease obligations. |
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In June, Seres entered into an amendment to its asset purchase agreement with Nestlé Health Science (Nestlé) under which Nestlé will pay Seres an aggregate $25 million (the Milestone Termination Payment), in two equal installments of $12.5 million on July 1, 2026 (which was received) and $12.5 million which is expected to be received on October 1, 2026, to buy out potential future VOWST net sales-based milestones. Seres sold the VOWST business to Nestlé Health Science in 2024. |
Second Quarter 2026 Financial Results
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Net income was $4.6 million for the second quarter of 2026, compared to a net loss of $19.9 million for the same period in 2025. The difference is primarily due to a $25 million Gain on Sale of the VOWST Business recognized in the second quarter of 2026 arising from the Milestone Termination Payment due from Nestlé. |
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Research and development expenses were $9.1 million for the second quarter of 2026, compared with $12.9 million for the same period in 2025, reflecting lower personnel-related expenses, facilities costs, transition services agreement (TSA) costs and SER-155 costs driven by lower activities in these areas and cost reduction efforts. |
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General and administrative expenses were $7.1 million for the second quarter of 2026, compared with $10.3 million for the same period in 2025, due to lower personnel-related expenses, facilities costs, professional services fees, and IT costs, including those related to IT services provided under the TSA. |
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In the second quarter of 2026, there was a $5.8 million impairment charge recorded related to the early termination of a portion of the Company's leased space at 101 Cambridgepark Drive. |
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There were no manufacturing services expenses in the second quarter of 2026, compared with $1.7 million in the second quarter of 2025, as the Company completed such services under the TSA at the end of 2025. |
Cash and Cash Runway
As of June 30, 2026, Seres had $15.6 million in cash and cash equivalents. Based on Seres' currently available cash resources, including the $12.5 million Milestone Termination Payment received from Nestlé on July 1, 2026, and the expected receipt of the remaining $12.5 million Milestone Termination Payment from Nestlé on October 1, 2026, and considering future operating plans, the Company expects to fund operations through the first quarter of 2027. This projection excludes proceeds from any potential future partnerships or other sources of capital.
About Seres Therapeutics
Seres Therapeutics, Inc. (Nasdaq: MCRB) is a clinical-stage biotechnology company developing novel live biotherapeutics products (LBP), designed to address unmet needs in oncology that can lead to interruption to patients' cancer care and/or mortality, and to treat inflammatory and immune (I&I) diseases, by modulating host function to protect and improve mucosal epithelial barrier integrity, induce immune homeostasis and tolerance, and prevent the colonization and overgrowth of pathogens in the gastrointestinal (GI) tract. The Company previously led the development and FDA approval of VOWST™, the first orally administered microbiome therapeutic, which was subsequently divested to Nestlé Health Science. SER-155, an investigational cultivated multi-strain biotherapeutic, which has received Breakthrough Therapy and Fast Track designations, is being advanced for the prevention of bloodstream infections in patients undergoing allogeneic hematopoietic stem cell transplant (allo-HCT), and is Phase 2 ready, pending receipt of funding. SER-155 is also being developed to address immune checkpoint inhibitor-related enterocolitis (irEC) to provide an immunosuppressive-free alternative and enable patients to continue their ICI cancer therapy. Having recently reported promising results from an IST, Seres is evaluating the design of a Phase 2 study in irEC. The Company is advancing IND-enabling studies for SER-603, which is in development for inflammatory bowel disease. Mechanistically, Seres' biotherapeutics target the mucosal epithelial barrier-immune interface and are optimized to modulate host function to increase mucosal epithelium integrity, induce immune homeostasis, and prevent the colonization and overgrowth of harmful bacteria in the GI tract. For more information, please visit www.serestherapeutics.com.
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