Seres Therapeutics has received US Food and Drug Administration (FDA) breakthrough therapy designation for its investigational programme, SER-155, aimed at decreasing bloodstream infections (BSIs) in the adult population.

The treatment is intended for those undergoing allogeneic hematopoietic stem cell transplant (allo-HSCT) for haematological-related malignancies.

Breakthrough status guarantees ongoing communication and support from the FDA, potentially accelerating the development process of SER-155.

A live biotherapeutic, SER-155 secured FDA fast track status in December 2023.

SER-155 also supports the decrease of infection and graft-versus-host disease (GvHD) risks in the same patient population.

The breakthrough designation was based on the Phase Ib clinical trial’s positive outcomes, where SER-155 led to a significantly lower incidence of bacterial BSIs versus placebo. It also indicated a briefer period of antibiotic treatment and decreased incidence of febrile neutropenia for the therapy-treated subjects.

GlobalData Strategic Intelligence

US Tariffs are shifting - will you react or anticipate?

Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.

By GlobalData

Seres Therapeutics CEO and president Eric Shaff stated: “We are thrilled that the FDA has granted breakthrough therapy designation to SER-155, underscoring the strength of our Phase Ib clinical data and the potential of the live biotherapeutic candidate to address one of the most significant complications faced by patients undergoing allo-HSCT.

“We are excited to advance the development of SER-155, working diligently to bring this innovative therapeutic to patients in need while also exploring its potential use in other high-risk patient populations to maximise its impact.”

In September 2024, the company reported that SER-155 led to a 77% relative risk reduction in BSIs, along with a decrease in systemic antibiotic exposure and febrile neutropenia incidents versus placebo.

The findings were observed through to day 100 post-transplant. The therapy was generally well tolerated with no serious adverse events related to treatment.

Seres is currently seeking a partner to help maximise the potential of the SER-155 programme while maintaining a capital-efficient development strategy.

In April 2023, Seres and Nestlé Health Science received FDA approval for Vowst, a treatment to prevent the recurrence of C difficile infection in adults.

Pharmaceutical Technology Excellence Awards - The Benefits of Entering

Gain the recognition you deserve! The Pharmaceutical Technology Excellence Awards celebrate innovation, leadership, and impact. By entering, you showcase your achievements, elevate your industry profile, and position yourself among top leaders driving pharmaceutical advancements. Don’t miss your chance to stand out—submit your entry today!

Nominate Now