Thank you for your interest.

We have completed the 013 Open Label trial enrollment at this time.

For information on the SER-109 Expanded Access Program, please visit

Recurrent C. diff infection can be a vicious cycle. But an investigational, oral medicine called SER-109 has shown promise at breaking the cycle of recurrence in C. diff.

In a pivotal Phase 3 clinical trial, patients who took SER-109 were less likely to have their infection recur than those treated with antibiotics alone. The results showed that SER-109 significantly decreased the chance of a recurrence of C. diff. Only 12.4% of patients who received SER-109 experienced a recurrence, compared to 39.8% of patients who received placebo.

Now, an open-label clinical study of SER-109 is enrolling patients with recurrent C. diff. If you have C. diff that has recurred after antibiotic treatment, you may qualify to participate. All patients in the study will receive treatment with SER-109.

Learn more about the studyFind a site near you

Why SER-109

The current standard of care for C. diff infection is antibiotics. However, antibiotic treatment alone is ineffective against dormant spore forms of C. diff, which can germinate and grow after antibiotics are completed, leading to a vicious cycle of recurrence. Repeated antibiotic exposure also depletes beneficial bacteria that inhibit C. diff, increasing the risk of recurrence.

SER-109 is designed to break the cycle of recurrent C. diff infection by simultaneously acting on multiple disease-relevant pathways to address key facets of the disease. SER-109 is an investigational, oral, biologically-derived microbiome therapeutic designed to prevent recurrence of C. diff infection.

Can I Take Part?

You may qualify to participate if you meet the following criteria:

  • Are 18 years or older,
  • Have had a C. diff infection in the past,
  • Now experiencing 3 or more unformed bowel movements per day over two consecutive days (potential current C. diff infection), and
  • Have been told by your physician you may have to take antibiotics.

If you think you may qualify, contact us to learn more.

Other eligibility criteria exist; please visit for detailed eligibility criteria, or speak to your doctor to learn more.