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For Patients

Thank you for your interest in learning more about Seres Therapeutics’ clinical trials. Below we’ve included information on our science and technology, and on why clinical trials are important to helping us bring treatments that are safe and effective to patients.

What is the microbiome?

The microbiome refers to the trillions of small organisms that live in or on your body. For a long time, scientists and doctors didn’t realize the important role the microbiome played in keeping humans healthy. In the last decade, the scientific community has begun to understand just how the microbiome helps to keep our bodies healthy, by fighting germs, resisting disease, and absorbing nutrients from the food we eat, to name just a few examples.

Seres has been studying the gut microbiome as a way to understand the treatment of disease. We believe that certain diseases flourish in bodies that have an imbalanced or disrupted microbiome, a condition known as dysbiosis, and that by developing medicines that treat dysbiosis directly, we are able to help bodies return to a healthy state.

Click here to read more about the microbiome on our website.

Our science and technology

Seres takes a new approach to the way we develop our therapeutic medicines. Our scientists study data from healthy microbiomes and compare them with microbiomes that have dysbiosis and are associated with a disease state. By comparing these data, and combining them with a deep understanding of the functional characteristics of different microbes, we are able to empirically identify alterations in the microbiome of healthy individuals that result in the disrupted diseased microbiomes. We then use our proprietary drug development platform to design and formulate compositions of microbes that deliver the missing functions back to the gut. By reestablishing these metabolic and immunological functions, we have been able to show that we can treat disease.

Click here to read more about our science and technology on our website

What are clinical trials and why should I participate?

Clinical trials are an important step in the drug development process. They help to ensure that our medicines are safe and effective. The Food and Drug Administration (FDA), the government organization that regulates medicines in the United States, will review the results of our clinical trials and decide whether to approve our medicines to be made available to the public.

For many patients who have found the usual course of treatment ineffective, clinical trials are an opportunity to be a part of the testing process for an investigational drug. Some patients may find that the investigational drug is more effective than other treatments they have tried. By taking part in clinical trials, patients can make an important contribution to ongoing research and to better understanding of a disease.

Our current clinical disease targets

Clostridium difficile infection (CDI) Our program SER-109, is developing a treatment to prevent recurring Clostridium difficile infection (CDI). Clostridium difficile is a bacteria that can cause unpleasant and sometimes serious symptoms, including frequent loose watery bowel movements (diarrhea) and stomach pain. Approximately 29,000 Americans die from CDI each year.

CDI most frequently occurs after a patient has received an antibiotic, typically within a hospital setting. Antibiotics are given to destroy harmful bacteria that cause disease, but occasionally can also destroy helpful bacteria that fight harmful bacteria such as Clostridium difficile.

We are evaluating SER-109 in CDI. Click here to read more about our CDI programs on our website.

Ulcerative Colitis (UC) We are also evaluating SER-287 in patients with UC, a serious chronic condition affecting approximately 700,000 individuals in the United States. UC results in inflammation of the colon and rectum and can result in debilitating symptoms, including abdominal pain, bowel urgency, and diarrhea.

Our current clinical trials

Below is a list of the clinical trials we currently have in progress. By clicking on the link, you will be redirected to the page on our website with more information on the clinical trial and how to participate.

  • SER-287: A Phase 2b Study (ECO-RESET) to evaluate the safety and efficacy of SER-287 versus placebo
  • SER-109: A Phase 3 Study (ECOSPOR III) to evaluate the safety and efficacy of SER-109 versus placebo (SER-109-012 Study)
  • SER-401: A Phase 1b Study to evaluate the safety and efficacy of SER-401 versus placebo

If you have any questions, please call 617.945.9626 x304.

SER-287 is revolutionizing ulcerative colitis treatment

Join our clinical trial


Take charge of your C. difficile with SER-109 for recurrent infections

Learn more about our clinical trial


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