By Rob Curran

Seres Therapeutics shares fell premarket after the biotechnology company warned it would lay off about 30% of its employees and pause development of an infection-prevention product candidate pending funding for a midstage trial.

Shares were down 26% to $10.40 in premarket trading.

Seres said it had submitted a final protocol to the Food and Drug Administration for a Phase 2 trial of its SER-155 product candidate, intended to prevent infections in adults undergoing certain stem-cell transplants for blood disorders. The company said it would continue seeking funding to conduct the midstage trial while pausing further investment in the program.

In the meantime, Seres is shifting focus to early-stage programs, including the SER-603 product candidate intended to treat inflammatory and immune conditions such as ulcerative colitis, Crohn's disease, and immune checkpoint related enterocolitis.

As of Sept. 30, Seres had $47.6 million in cash and cash equivalents. The company said Thursday's move would extend its cash runway, or the amount of time before exhaustion of reserves, until the end of the third quarter. In September, Seres divulged plans to cut its staff by 25%.

Seres's major breakthrough, so far, was receiving FDA commercial approval for VOWST, an oral medication based on the body's microbiome.

Write to Rob Curran at rob.curran@dowjones.com

(END) Dow Jones Newswires

February 12, 2026 07:53 ET (12:53 GMT)

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