Seres Therapeutics Inc. (MCRB) is making some tough calls. The biotech company announced Thursday it's hitting pause on its lead drug program and letting go of roughly 30% of its staff in a bid to conserve cash and refocus its priorities. Investors weren't thrilled—shares dropped more than 16% in premarket trading.
The moves come as Seres shifts its attention toward emerging programs in inflammatory and immune diseases, raising questions about what happens next for its current pipeline and how the company plans to fund its future.
What's Happening With SER-155
Seres has wrapped up the protocol design for its Phase 2 study of SER-155, a treatment for patients undergoing allogeneic hematopoietic stem cell transplant. That sounds like progress, except the company is now pausing further investment in the program while it hunts for external funding to actually run the trial.
The company says it's concentrating operational resources on what it calls "high-value earlier-stage pipeline programs" while keeping the door open for SER-155 funding down the line.
There's still one piece of SER-155 news on the horizon. An investigator-sponsored study of the drug in immune checkpoint-related enterocolitis is fully enrolled, and Seres will support the readout of those clinical results. Expect that data in early Q2 2026.
Going forward, Seres is prioritizing its early-stage programs, particularly SER-603. That candidate targets inflammatory and immune indications like ulcerative colitis, Crohn's disease, and immune checkpoint-related enterocolitis. The company says it's in discussions with potential partners about collaborations in these areas.
The pivot could open doors for partnerships and funding opportunities, but it also highlights immediate concerns about the company's financial position and near-term viability.
Staff Cuts and Cash Runway
The workforce reduction of approximately 30% is designed to stretch Seres's cash through Q3 2026, giving the company breathing room to advance its early-stage live biotherapeutic programs for inflammatory and immune diseases while pursuing potential collaborations.
Previously, with a cash balance of $47.6 million, the company had expected to fund operations through Q2 2026. The restructuring buys an extra quarter.
The stock's decline stands out against a relatively upbeat market backdrop. On the previous trading day, the Nasdaq gained 0.32% and S&P 500 futures rose 0.3%. The selloff in Seres shares suggests investors are focused squarely on company-specific concerns rather than broader market trends.
Technical Picture Looks Rough
The chart isn't doing Seres any favors. The stock is currently trading 24.4% below its 20-day simple moving average and 33% below its 100-day SMA—classic signs of a bearish trend. Over the past year, shares have dropped 13.86% and are sitting much closer to their 52-week lows than highs, reflecting the ongoing operational challenges.
The Relative Strength Index sits at 42.50, which puts it in neutral territory. That means the stock isn't technically overbought or oversold. However, the MACD is sitting below its signal line, pointing to bearish momentum.
Put together, the neutral RSI and bearish MACD suggest mixed signals and continued pressure on the stock.
- Key Resistance: $13.50
- Key Support: $11.00
MCRB Price Action: Seres Therapeutics shares were down 16.25% at $11.80 during premarket trading on Thursday, according to market data.
