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A successful SER-109 Phase 1b study has been completed, and the results were published in the Journal of Infectious Diseases.

Based on the successful SER-109 Phase 1b results, Seres completed and reported a placebo controlled Phase 2 study (ECOSPOR). Following the Phase 2 results, Seres performed a detailed and comprehensive review of the SER-109 program. The summary of these finding can be found here.

Seres plans to initiate a new SER-109 Phase 2 clinical study (ECOSPOR III) in patients with multiply recurrent C. difficile infection. The ECOSPOR III study design was finalized following a positive Type B meeting with the FDA. The FDA has agreed that this new trial may qualify as a pivotal study with achievement of a persuasive clinical effect and addressing FDA requirements, including clinical and statistical factors, an adequately sized safety database, and certain CMC parameters.

About Clostridium difficile

Clostridium difficile (C. difficile) is a bacterium that causes an infection of the gut. Most doctors and patients call this infection “C. diff” for short. C. difficile infection (CDI) can cause many loose watery bowel movements (diarrhea) and painful stomach cramps. The main cause of CDI is antibiotics, which wipe out the good bacteria of the gut, which may permit some bad bacteria, like C. difficile, to take over and cause infection.

Many patients can be successfully treated for CDI with antibiotics that target these bad bacteria. However, some patients keep getting the infection again and again. Recurrent C. diff is a major problem because there are no good methods to prevent the infection from recurring. Part of the problem is that the good bacteria are still missing from the gut. Without those good bacteria, the patient has no defense against getting CDI again—even if antibiotics stop the diarrhea for a little while.

For someone with recurrent CDI, diarrhea is a daily problem that can be frequent and start without warning. Patients with frequent diarrhea and stomach discomfort have trouble doing many of their usual daily activities. Some even have trouble leaving the house. However, the good news is that research is going on right now to find a medicine to prevent CDI from recurring.

Our Lead Candidate SER-109

Learn more about SER-109, our lead development candidate


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