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SER-262 (SER-262-001 STUDY)

SER-262-001 is a Phase 1b clinical study evaluating the safety, tolerability and effectiveness of SER-262 versus placebo in adults diagnosed with their first episode of Clostridium difficile infection (CDI) following standard-of-care antibiotics to treat CDI. The study is currently enrolling at sites in the United States. This study is a Phase 1b study because SER-262 is being evaluated in patients diagnosed with CDI rather than in healthy adults. The full name of the study is: “A Phase 1b Randomized, Double-Blind, Placebo-Controlled, Ascending Single Dose Study to Evaluate the Safety, Tolerability and Efficacy of SER-262 in Adults with Primary Clostridium difficile Infection (CDI) to Prevent Recurrence”

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 can wipe out good bacteria in the gut, which may permit bad bacteria, like C. diff, to take over and cause infection.

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

Who is eligible for the SER-262-001 Study?

You may be eligible to participate in SER-262-001 if you:

  • Are 18 years of age or older
  • You have been diagnosed as having CDI for the first time
  • Will soon be, or are currently taking antibiotics to treat CDI
  • Your infection (diarrhea) has stopped with treatment with the antibiotics

What should I know about the study medicine?

SER-262 is an investigational medication. An investigational medicine is a product that is still being tested and has not been approved by regulatory authorities, including the Food and Drug Administration (FDA), for commercial sale. This means SER-262 can only be used in research studies. Your doctor cannot prescribe it to you.

SER-262 is a preparation of twelve different types of bacteria in spore form that are put into capsules. Bacterial spores are dormant (inactive) forms of bacteria. All 12 types of bacteria in SER-262 are normally present in the healthy human gut. SER-262 is delivered in 4 oral capsules and is intended to help restore healthy bacteria in the gut and may keep CDI from returning.

What will happen during the study?

You will be asked certain questions to find out if you can join the study. If eligible, you will be provided with additional information and asked to give us written permission to join the study.

If you are eligible, you will be randomized, like drawing a name out of a hat, to receive a single dose of SER-262 or placebo. A placebo is a capsule that looks like the drug but contains no active drug.

This is a double-blinded study. That means that neither you nor the study doctors and study staff will know which patients get SER-262 and which patients get the placebo. The results will help researchers tell if SER-262 is working. It will also help the study doctors tell if there are any side effects of SER-262 to be concerned about.

Participation in the study will last approximately 26 weeks and will include 4 scheduled visits at the clinic (1 screening visit, a study treatment visit on Day 1, and 2 post-treatment visits at Week 4 and Week 8). These visits will include a physical exam, blood draw, and urine collection. Your stool will also be collected (at home or at the clinic) as part of this study. You will be contacted regularly by phone up to 24 weeks post-treatment to ask about your health and about any new episodes of CDI. If your CDI comes back during the study, you will be asked to return to the clinic for an unscheduled visit.

What is involved in enrolling and participating in this study?

You do not have to be in the study. You should discuss your choices for treating your CDI with your doctor.

If you do choose to be in the study, you may leave the study at any time and for any reason. Your decision will be respected, there will not be any penalties, and it will not affect your routine medical care and/or treatment. However, if you leave the study, you will not be allowed to rejoin the study.

How do I enroll in the study?

The SER-262-001 study is open for enrollment. More information regarding the study can be found on

You can find out if there is a study site near you by reviewing the clinical study site locations on the website.

Deciding to be in a clinical trial is an important decision. If a doctor in the study thinks you should be in the study, you will be told everything you should know before you join, including the risks and potential benefits of participating.

What should I know about research studies?

Drug (pharmaceutical) companies conduct research studies like SER-262-001 to learn more about investigational medications to determine whether they may be safe and effective before they may be made available to the public.

The results of the SER-262-001 study will provide more information about the potential safety and effectiveness of SER-262.

By taking part in this study, participants will be making an important contribution to ongoing C. diff research.

SER-262 (SER-262-001) Clinical Trial
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