Seres Therapeutics (MCRB) Q3 2026 earnings summary

Executive summary

• Q3 revenue was $593K and net loss was $16.286M; cash and cash equivalents were $17.528M at Sept. 30, 2026.

• SER-155 allo-HCT Phase 2 remains paused pending funding, while planning continues for an irEC prevention study and earlier-stage programs.

• In an investigator-sponsored SER-155 irEC trial, 12 of 15 participants (80%) achieved an immunosuppressive-free diarrhea response by Day 15; no drug-related serious adverse events were observed.

Financial highlights

• Q3 2026 revenue was $593K vs. $351K YoY, all from CARB-X grant revenue; nine-month revenue was $1.687M vs. $351K.

• Q3 operating expenses were $16.745M vs. $22.828M YoY; nine-month expenses were $60.019M vs. $74.945M. Q3 R&D and G&A expenses were $5.6M and $5.4M, respectively.

• Q3 net loss was $16.286M vs. net income of $8.204M YoY; nine-month net loss was $31.618M vs. net income of $21.031M.

• Q3 2025 results included a $27.222M VOWST business gain; nine-month 2026 results included the $25M VOWST milestone termination gain.

• Nine-month cash used in operations was $49.231M; investing cash inflow was $12.566M and financing cash inflow was $2.895M. Cash, equivalents and restricted cash ended at $20.664M.

Outlook and guidance

• Available cash, including the $12.5M VOWST milestone termination payment received in October, is expected to fund operations through Q1 2027; additional funding is expected to be required thereafter.

• SER-155 allo-HCT Phase 2 remains paused pending funding; the planned study is expected to enroll ~248 participants and include an interim analysis.

• FDA submission of the SER-155 irEC prophylaxis study design is expected in Q1 2027, with dose optimization and evaluation in patients initiating ICI therapy; development is funding-dependent.

• SER-428 IND readiness is targeted by end-2026; further development depends on grants or other funding. SER-603 remains in preclinical development with IND-enabling work ongoing.

• R&D and G&A expenses were expected to decrease in 2026 vs. 2025 following workforce reductions, TSA completion and lower program and facilities spending.