First Potential Microbiome Drug Has FDA Setback
A company called Seres Therapeutics (NASDAQ-MCRB) is the first company to take microbiome research and digestive health expertise to the next level. The company has entered into FDA clinical trials with a product for treating clostridium difficile infection (CDI), an infection of the large intestine caused by a pathogenic bacteria called clostridium difficile. CDI affects over 500,000 annually and last year led to approximately 29,000 deaths, according to the U.S. Center for Disease Control. Due to the CDI risk, the CDC has classified clostridium difficile bacterium as an “urgent Threat.”
Seres’ treatment, called SER-109, has shown very promising results in early trials, and they recently entered into an FDA Phase 2 study to measure efficacy and safety. Unfortunately, the company received disappointing initial results from their Phase 2 trial last Friday, which surprised investors who follow the company and led to a $500 million drop in the company stock market value.
SER-109 is biologic drug that's an extension of a highly successful treatment already in use, called a fecal microbiome transplant, or FMT. In the FMT procedure, gastroenterologists transplant stool from a healthy volunteer into the colon of a patient with CDI, which basically gives the patient a new population of healthy gut bacteria.
With SER-109, Seres took the idea of stool transplant one step further by processing healthy volunteer stool samples to isolate the “good” gut bacteria. According to Seres Therapeutics, SER-109 contains over 50 species of the gut bacteria called Fermicutes, and the treatment plants these bacteria in the digestive tract of CDI patients, which treats the CDI infection by establishing a “good” gut bacteria population that ousts the CDI.
Gastroenterologists we communicated with say FMT is 95% successful on the first attempt, however, the process is time consuming, requires physician assistance, and has an “ick” factor that makes the process somewhat unpleasant. The positive results of FMT treatments, and the difficulties in using it with patients is why an orally administered capsule like SER-109 is so exciting.
What happened with SER-109 in Phase 2?
According to information provided by Seres Therapuetics during a recent conference call, the story is not over. They have a great deal of data to review, as well as questions to investigate. For example, the Phase 2 data for patients over 65 years old showed the same efficacy as their early trials. The company was very open reagarding what they don’t yet know about the human microbiome and the potential of probiotics as disease treatments. In our opinion, the approach taken by Seres is novel and very interesting, and the SER-109 setback is not a failure of probiotics in general or for specific conditions like CDI.