Seres Therapeutics Inc. (NASDAQ: MCRB) Completes Enrolment in ECOSPOR IV SER-109 Study

Seres Therapeutics Inc. (NASDAQ: MCRB) has announced the completion of enrolment of 300 participants in the ECOSPOR IV open-label trial evaluating SER-109. SER-109 is an experimental oral microbiome therapy for recurrent C. difficile infection (rCDI). 

Seres to launch expanded access program bye end of 2021

The SER-109 safety database enrollment goal of 300 individuals was met in tandem with a previously completed third phase trial, ECOSPOR III. To support a BLA submission, the FDA requires the company to show SER-109’s safety in at least 300 subjects that have received the dose the company will commercialize, per standard FDA guidance. Seres expects to finish enrollment in the open-label trial and work with the FDA on launching an expanded access program by the end of 2021.

CEO Eric Shaff said, “This is a meaningful milestone for the company as it positions us for a BLA submission that, if approved, could make SER-109 the first-ever FDA-approved microbiome therapeutic. We are working tirelessly alongside our commercial collaborator, Nestlé Health Science, to bring this potentially revolutionary therapeutic to recurrent C. difficile patients, who urgently need safer and more effective treatment options to reduce the likelihood of recurrent disease.”

Phase III trial attained primary endpoints. 

The company had previously reported topline data showing that the SER-109 ECOSPOR III Phase 3 study attained primary endpoints eight weeks after treatment. In addition, the study showed a statistical significance of 30.2% absolute reduction in C. difficile infection recurrence rate.

Seres Chief Medical Officer Lisa von Moltke said, “SER-109 has the potential to change the treatment paradigm and meaningfully improve medical outcomes for the more than 170,000 recurrent CDI patients in the U.S. suffering from this deadly disease each year, including over 20,000 deaths annually. Reaching this enrollment milestone is critical to achieving that goal, and we are grateful to these trial participants, their families and healthcare providers for their contributions.”