Experimental "SER-109" for the Treatment of Adults With Recurrent Clostridium Difficile Infection (bacteria in the colon)

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"Have you had Clostridium difficile infection (CDI) at least three times in the past 9 months?"
Age: 18 years or older
Healthy Volunteers: No
Keywords: Clostridium difficile infection, CDI, infectious diseases
Type: Drug study, Phase 3
5 Participants
The purpose of this study is to see how safe and effective the Study Drug is. We will compare it to a placebo, a capsule containing no active drug. We want to see how well it works to keep Clostridium difficile infection (CDI) from coming back in people who have recovered from three or more episodes of CDI. Medical literature suggests that as many as 60% (6 out of 10 patients) will have another episode of CDI if they have already had three or more episodes.

Clostridium difficile (C.diff) is a type of bacteria that is present in the environment, and in a small percentage of healthy people. C .diff can be present in low amounts, as a part of the bacteria in the intestine or colon. Patients with a history of antibiotic use may develop an infection called C. diff infection (CDI). This is because antibiotics can reduce amount of normal healthy bacteria found in the large intestine or colon, which allows for the growth of C. diff bacteria leading to CDI.

C .diff bacteria makes a toxin which causes diarrhea that can be very mild and last a few days, or may be severe causing frequent diarrhea, abdominal pain, and may even require life-saving surgery. After recovering from CDI, the infection may come back in days, weeks, months or years later in some people. This is called recurrent CDI and is a significant medical condition for many people.
This study requires

If you decide to participate, you will be assigned by chance (like the flipping of a coin), to receive one of two study treatments: Study Drug (SER-109) or a placebo. You will have a 1 out of 2 chance, or a 50% chance of receiving the Study Drug. This study is double-blinded, which means that neither you nor your study doctor or the study staff will know which study drug you are receiving. However, the study drug you receive will be made known in the case of an emergency.

If you are assigned to receive the Study Drug, you will receive single daily doses of 3×107 spore colony forming units (SCFU) in 4 capsules administered orally (by mouth) each day for 3 consecutive days. If you are assigned to receive placebo, you will receive matching placebo containing no active drug in 4 capsules administered by mouth each day for 3 consecutive days.

You will be instructed to take all study drug doses in the morning after an overnight fast of 8 or more hours (nothing by mouth except for small amounts of water). You will need to remain fasting for up to 60 minutes after you take the study drug. You must come to the clinic or have a home visit on Day 2 and Day 3 to witness you taking the study drug.

If you take part in this research, you will be expected to:

  • Come to all of your study visits and follow the instructions given to you by the study doctor and study staff

  • Let your study doctor know of any changes in your health while you are in this study

  • Check with your study doctor before starting to take any new medications or remedies

  • Not take part in any other research studies while you are taking part in this study

  • Notify your study doctor immediately if you or your partner becomes pregnant

  • Notify your study doctor immediately if you choose to stop your participation in the study for any reason, so that a plan can be made for your continued medical care

  • Return to the clinic for your final study visit, as described above Please do not give blood for non-study purposes, unless medically required, while you are taking part in this study. The following drugs/therapies are prohibited for the duration of the study:

  • Probiotics

  • Loperamide

  • Diphenoxylate/atropine

  • Cholestyramine

  • Opiate treatment unless on a stable dose (Note: Short term opiate use is permitted (e.g., for a dental extraction).

  • Chemotherapy, radiotherapy, or biologic treatment for active malignancy

  • Oral Fidaxomicin, oral metronidazole, oral vancomycin, used to treat for anything else other than CDI recurrences

  • Fecal Microbiota Transplantation (FMT) prior to CDI recurrence in the study

Who can participate

Inclusion criteria:

  1. Signed informed consent prior to initiation of any study-specific procedure or treatment. The subject must be able to provide written informed consent and understand the potential risks and benefits from study enrollment and treatment.
  2. Male or female subject ≥ 18 years of age.
  3. A qualifying episode of CDI as defined by:
  4. ≥ 3 unformed stools per day for 2 consecutive days
  5. A positive C. difficile stool toxin assay.
  6. The requirement of CDI SOC antibiotic therapy (defined as 10 to 21 days of treatment with vancomycin [125 mg QID] and/or fidaxomicin [200 mg BID]).
  7. An adequate clinical response following SOC antibiotic therapy, defined as (<3 unformed stools in 24 hours) for 2 or more consecutive days before randomization.

Exclusion criteria:

  1. Female subjects who are pregnant, breastfeeding, lactating, or planning to become pregnant during the study.
  2. Known or suspected toxic megacolon and/or known small bowel ileus.
  3. Admitted to or expected to be admitted to an intensive care unit for medical reasons (not just boarding). Note: nursing homes, rehabilitation, assisted living centers and acute care hospitals are acceptable.
  4. Absolute neutrophil count of <500 cells/ml3
  5. Major gastrointestinal surgery (e.g. significant bowel resection or diversion) within 3 months before enrollment (this does not include appendectomy or cholecystectomy), or any history of total colectomy or bariatric surgery (bariatric surgery which does not disrupt the gastrointestinal lumen, i.e., restrictive procedures such as banding, are permitted).
  6. History of active inflammatory bowel disease (ulcerative colitis, Crohn's disease, microscopic colitis) with diarrhea believed to be caused by active inflammatory bowel disease in the past 3 months.
  7. Concurrent intensive induction chemotherapy, radiotherapy, or biologic treatment for active malignancy (subjects on maintenance chemotherapy may only be enrolled after consultation with the study medical monitor).
  8. Any history of fecal microbiota transplantation (FMT).
Benefits and risks of participating

If you agree to participate in this study, there may or may not be a direct benefit to you. If you receive the active study drug, another episode of CDI may be prevented but there is no guarantee. Study participants receiving the placebo are not expected to benefit.


As with any investigational treatment, it is not possible to predict all of the unwanted side effects. Your doctor will discuss potential risks with you.
If you agree to take part in this research study, we will compensate you $76 for travel expenses for each of the following completed visits: Screening, Day -1, Day 1, Week 1, Week 8, Week 24, Recurrence, ET, Day 2, and Day 3, up to a total of $760.

You may receive additional compensation of $76 if you have any unscheduled CDI recurrence visits.
Study duration and period
We expect that you will be in this research study for up to 27 weeks and will include: Up to 6 study visits at the clinic AND regularly scheduled telephone calls
Recruitment period
From Jan. 17, 2018
UC Davis Medical Center
2315 Stockton Boulevard
Sacramento, CA 95817
Research Topic
  • Clostridium Difficile Infection

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