Summary of Seres Therapeutics Corporate Update Conference Call Company Overview - **Company**: Seres Therapeutics (NasdaqGS: MCRB) - **Focus**: Development of live biotherapeutic products targeting inflammatory and immune diseases, particularly in the context of microbiome therapies Key Points and Arguments Management Transition and Leadership - Richard N. Kender has been appointed as Executive Chair and Interim CEO, emphasizing confidence in the company's scientific foundation and leadership team [2][3] - The leadership team includes Dr. Matthew Henn (President and CSO), Kelly Brady (COO), and Marella Thorell (CFO), all of whom are pivotal in advancing the company's strategic goals [4][5] Product Development and Pipeline - **VOWST**: The first oral microbiome therapeutic, which has validated the company's platform and demonstrated its ability to navigate complex regulatory pathways [5] - **SER-155**: A key program targeting immune checkpoint inhibitor-related colitis (irEC), with clinical data expected in Q2 2026. This condition affects up to 50% of patients receiving immune checkpoint inhibitors [7][15] - **SER-603**: A preclinical stage biotherapeutic aimed at inflammatory bowel disease (IBD), addressing unmet needs for non-immunosuppressive treatment options [8][10] Clinical Trials and Collaborations - Ongoing collaboration with Memorial Sloan Kettering Cancer Center for the SER-155 study, which is fully enrolled with 15 participants [13][14] - SER-155 has received breakthrough therapy designation, facilitating interactions with the FDA for further development [16] Financial Position and Strategy - As of December 31, 2025, Seres had approximately $45.8 million in cash and cash equivalents, with expectations to fund operations through Q3 2026 [18] - The company has implemented cost-reduction measures, including workforce reductions, to extend its cash runway [18] - A focus on securing funding and collaborations to advance the pipeline and create shareholder value [19] Market Opportunity - The potential market for irEC therapies is significant, given the success of immunotherapeutics like Merck's Keytruda, which reached $32 billion in global sales in 2025 [7] - SER-603 aims to address the chronic nature of IBD and the need for safe, durable treatment options, presenting a substantial commercial opportunity [8][10] Additional Important Content - The company is exploring collaborations with entities that have established franchises in IBD to enhance the development of SER-603 [11] - The development of an oral liquid formulation of SER-155 is underway, targeting patients unable to take capsules, which could have broad applicability [11] This summary encapsulates the critical aspects of Seres Therapeutics' corporate update, highlighting the company's strategic direction, product pipeline, financial status, and market opportunities.

Core Insights - Seres Therapeutics is advancing its corporate strategy focused on live biotherapeutic programs targeting inflammatory and immune diseases, particularly inflammatory bowel disease and immune checkpoint-related enterocolitis, with clinical data from the SER-155 study expected in Q2 2026 [1][3][5] Leadership Changes - Richard N. Kender has been appointed as Executive Chair and Interim CEO, bringing over 35 years of biopharma experience, while previous co-CEOs will continue in their roles as Chief Legal Officer and Chief Financial Officer [2][4][5] Clinical Development - SER-155 is ready for Phase 2 trials for patients undergoing allogeneic hematopoietic stem cell transplant to treat hematologic malignancies, with ongoing efforts to secure funding for the program [1][5][11] - The SER-155 study is fully enrolled with 15 participants, and initial clinical data is anticipated in Q2 2026, focusing on safety, efficacy, and pharmacology [11][13] Financial Position - As of December 31, 2025, Seres had approximately $45.8 million in cash and cash equivalents, with expectations to fund operations through Q3 2026 [8][10] Pipeline Updates - The company is also advancing SER-603, a novel live biotherapeutic candidate aimed at treating inflammatory bowel disease, with IND-enabling activities underway [11][13]

Summary of Seres Therapeutics FY Conference Call Company Overview - **Company**: Seres Therapeutics (NasdaqGS:MCRB) - **Industry**: Biotechnology, specifically microbiome therapy - **Key Products**: - VOWST for recurrent C. difficile infections - SER-155 for reducing GI infections, bacteremia, and graft-versus-host disease in allogeneic hematopoietic stem cell transplant patients - SER-603 for ulcerative colitis and Crohn's disease [1][1][1] Core Technology and Development - **Microbiome Technology**: Seres utilizes a platform to design drugs as consortia of bacteria with specific functional properties, targeting pathways related to human diseases [4][4][4] - **Manufacturing Expertise**: Unique skills in cultivating and producing microbiome therapies, with established FDA CMC processes [6][6][6] SER-155 Program - **Unmet Medical Need**: SER-155 addresses high infection rates in stem cell transplant patients, which can reach around 4% even with standard antibiotic prophylaxis. The infection rate is increasing due to new treatment protocols [9][10][10] - **Clinical Data**: Phase 1B study showed a 77% relative risk reduction in bloodstream infections compared to placebo, along with lower antibiotic use and febrile neutropenia [13][13][13] - **FDA Engagement**: Positive feedback from the FDA on the design of the upcoming Phase 2 study, which will include 248 patients and focus on reducing bloodstream infections [17][18][18] Commercial Opportunity - **Market Size**: Approximately 40,000 allogeneic stem cell transplants occur annually worldwide, with a tight commercial footprint allowing for efficient education and adoption of new products [20][20][20] - **Pricing Strategy**: The estimated cost of a stem cell transplant is $400,000, with an additional $200,000 incurred during infections. SER-155 is expected to be priced at a premium due to its value proposition [23][23][23] Future Development and Indications - **Potential Indications**: SER-155 may also be applicable in autologous transplants and broader cancer populations, with an estimated 60,000 autologous transplants and 500,000 cancer patients annually [26][27][27] - **SER-603 Development**: SER-603 aims to treat ulcerative colitis and Crohn's disease, leveraging advancements in microbiome research to target specific patient populations more effectively [34][35][35] Financial Position - **Funding Status**: Seres ended the third quarter with $48 million, which has since increased to over $50 million. This funding is expected to last through the second quarter of the following year, focusing on advancing the Phase 2 study for SER-155 [40][40][40]

Seres Therapeutics Overview - Seres' VOWST, the first-ever oral live microbiome therapeutic, received FDA approval in April 2023 for preventing C difficile infection recurrence, demonstrating approximately 88% sustained clinical response rate[6,9] - The sale of the VOWST asset, completed in September 2024, provided Seres with capital to support pipeline advancement and streamline the organization[9,10] - As of June 30, 2025, Seres had approximately $45.4 million in cash and cash equivalents, projecting a cash runway into Q1 2026[92] SER-155 Clinical Development - SER-155 Phase 1b data in allo-HSCT showed a 77% relative risk reduction in bacterial bloodstream infections (BSIs) compared to placebo[6,45,92] - SER-155 Phase 1b data also showed significantly lower mean cumulative exposure to systemic antibacterials/antimycotics compared to placebo (9.2 days vs 21.1 days)[45,50] - SER-155 Phase 1b data also showed a lower incidence rate of febrile neutropenia in SER-155-treated subjects vs placebo[46] - A Phase 2 study protocol for SER-155 in allo-HSCT was submitted to the FDA in May 2025, with study commencement dependent on funding and aiming to enroll 248 patients[6,31,78] Pipeline and Future Opportunities - Seres is developing SER-147 to prevent infections in chronic liver disease patients, with preclinical data showing a 1-3 log reduction of E coli in in vitro models[6,80] - Seres is also developing SER-603 to target inflammatory drivers of Inflammatory Bowel Disease (IBD)[83] - Seres is engaging with multiple parties regarding various deal structures to secure capital for the clinical advancement of SER-155 and other live biotherapeutic product candidates[6,78,92]

SER-155 Clinical Data and Development - SER-155 Phase 1b study showed a 77% relative risk reduction in bacterial bloodstream infections (BSIs) compared to placebo[6,44,83] - SER-155 treatment was associated with significantly lower mean cumulative exposure to systemic antibacterials/antimycotics compared to placebo[44,49] - The company plans to submit a Phase 2 protocol to the FDA in Q2 2025, incorporating FDA feedback[6,31,73,83] - The FDA granted SER-155 Breakthrough Therapy designation in December 2024[6,73,82] Financial Position and Strategy - The VOWST asset sale to Nestlé closed in September 2024, providing capital to support SER-155 advancement[6,9,10,12,83] - The VOWST asset sale included a $100 million upfront payment, less ~$20 million in net obligations, a $15 million equity investment, and a $60 million prepaid sales-based milestone at closing[10] - As of March 31, 2025, the company had approximately $588 million in cash/cash equivalents, projecting a cash runway into Q1 2026[83] - The company is pursuing a strategic partnership for SER-155 to accelerate the next study in allo-HSCT and expand to multiple target populations[6,73,83] Pipeline and Platform - VOWST was FDA approved in April 2023 to prevent the recurrence of C difficile infection in adults, demonstrating an approximately 88% sustained clinical response rate[6,9] - SER-155 is being developed initially in allo-HSCT, with potential to expand to autologous-HSCT, blood cancers, and CAR-T recipients[6,30] - SER-147 is designed to prevent infections in chronic liver disease, with IND-enabling activities underway[6,30,74,82]

Financial Data and Key Metrics Changes - Seres reported a net loss from continuing operations of $15.7 million for Q4 2024, compared to a net loss of $34.7 million for the same period in 2023, indicating a significant improvement [49] - For the full year 2024, the net loss from continuing operations was $125.8 million, down from $190.1 million in 2023, primarily due to lower operating expenses of approximately $74 million [49] - Research and development (R&D) expenses for Q4 2024 were $12.8 million, down from $23 million in Q4 2023, reflecting a focus on the lead program SER-155 [51] - General and administrative (G&A) expenses for Q4 2024 were $12.5 million, compared to $14 million in Q4 2023, also showing cost management efforts [52] Business Line Data and Key Metrics Changes - The company has made substantial progress with SER-155, a biotherapeutic aimed at preventing bloodstream infections in allo-HSCT patients, showing a 77% relative risk reduction in bloodstream infection rates in a Phase 1b study [10][23] - Manufacturing services expenses were introduced as a new category in 2024, amounting to $3.5 million for Q4 2024, related to services under the transition agreement with Nestle [53] Market Data and Key Metrics Changes - The commercial opportunity in allo-HSCT alone is considered sizable, with approximately 9,300 procedures conducted annually in the US and around 20,000 in Europe [43] - Market research indicates a high unmet need for preventing bacterial bloodstream infections, with healthcare professionals and payers expressing a desire for better prophylactic options [40][41] Company Strategy and Development Direction - The company is focused on advancing SER-155 and exploring partnerships to maximize its potential, with plans to submit a draft study protocol to the FDA in Q2 2025 [21][56] - SER-155 is positioned to address not only allo-HSCT but also other medically vulnerable patient populations, including those with inflammatory bowel disease [35][61] Management's Comments on Operating Environment and Future Outlook - Management expressed optimism about the progress made with SER-155, highlighting the breakthrough therapy designation received from the FDA and the constructive feedback from the agency [58] - The company aims to operationally prepare for the next study of SER-155 while seeking additional guidance from the FDA [15][19] Other Important Information - The VOWST sale transaction closed in September 2024, providing Seres with $155 million, which has allowed the company to retire its debt and simplify operations [46][48] - The company expects to fund operations into Q1 2026 based on its current cash position and anticipated payments from the VOWST transaction [55] Q&A Session Summary Question: Feedback from the FDA regarding manufacturing and patient enrollment - Management indicated that the FDA's feedback was comprehensive and that they are confident in their manufacturing plans moving forward [67][75] Question: Recent FDA feedback relative to expectations and Phase 2/3 study differences - Management found the FDA's feedback constructive and noted that a Phase 2/3 study would require more pre-specification and discussions with the agency [80][83] Question: Safety database considerations based on VOWST experience - Management acknowledged the importance of the safety database and indicated that discussions with the FDA would evolve as more data is generated [88][92] Question: Potential size of the next study and additional efficacy endpoints - Management suggested that a standalone Phase 2 study could provide meaningful data quickly, with additional endpoints including febrile neutropenia and antibiotic use being considered [100][102]

Seres Therapeutics Investor Presentation March 2025 Transforming patient outcomes using proprietary consortia of live biotherapeutics Seres Therapeutics Investor Presentation March 2025 Strong Foundation Positive SER-155 Phase 1b Data in Allo-HSCT Blockbuster SER-155 Opportunity • Initial SER-155 development in allo-HSCT • Potential to initiate multiple clinical trials for additional indications • SER-155 represents multi- billion net sales opportunity across indications (e.g., autologous-HSCT, blood cancer ...