MCRB · Seres Therapeutics, Inc.

Seres Therapeutics announced Q1 2026 financial results showing a net loss of $19.9 million, a shift from $32.7 million net income in Q1 2025 primarily due to a one-time $50 million installment from Nestlé related to VOWST transition services and $6.3 million in reimbursements. Operating expenses fell approximately $6 million year-over-year to $21.3 million, driven by lower general and administrative costs ($8.1 million vs $11.9 million) from reduced personnel, professional services, and IT expenses no longer reimbursed under the TSA, elimination of $3.5 million in manufacturing services completed by end-2025, and a modest R&D increase to $13.2 million from higher facilities and manufacturing costs previously offset by Nestlé. Cash stood at $29.8 million as of March 31, 2026, down from $45.8 million at year-end, with runway into Q3 2026 amid disciplined allocation and pursuit of partnerships or financing. Operationally, focus remains on live biotherapeutics in inflammatory and immune diseases, with a key near-term catalyst being topline data in weeks from a completed investigator-sponsored SER-155 trial in irEC at Memorial Sloan Kettering, where enrollment of 15 patients is done; positive results could expand indications given irEC's prevalence in up to 50% of immune checkpoint inhibitor patients. SER-155 is Phase 2-ready for preventing bloodstream infections in allo-HSCT patients, supported by prior Phase 1b data showing 77% relative risk reduction and microbiome shifts, with funding efforts ongoing. Preclinical SER-603 for IBD advances via IND-enabling work and DDW poster recognition, while SER-428 oral liquid formulation progresses under CARB-X grant for ICU patients.