In Microbiome Milestone, Finch Therapeutics C. diff Pill Bests Placebo

Xconomy Boston — 

Ten years ago Mark Smith was at MIT doing basic research into the microbiome. Now, as CEO of Finch Therapeutics Group, Smith has hard data to back up his company’s thesis that using “good” bacteria as a therapeutic can best a placebo when it comes to at least one condition: a recurrent C. difficile infection.

Somerville, MA-based Finch on Friday reported encouraging preliminary data from a clinical trial of its investigational oral microbiome drug, CP101. In the Phase 2 study, 74.5 percent of patients who received a single dose following a typical course of antibiotic therapy achieved a “clinical cure” after eight weeks. Of those who received a placebo following antibiotics, 61.5 percent achieved that goal. The difference was statistically significant, according to Finch.

For the trial Finch enrolled a total of 206 patients across 51 US and Canadian clinical research sites in PRISM3, which the company describes as the largest placebo-controlled study to date testing an oral microbiome drug.

CP101 is made up of live microbes sourced from donors, material used after it is screened for pathogens. The idea behind the experimental therapeutic is to end infection recurrences by bringing the gut microbiome back to a state in which it’s healthy enough to prevent future C. diff colonization. While antibiotics can tamp down the growth of C. diff and other pathogens, they don’t restore a healthy microbiome, which can lead to reinfection.

Smith (pictured) says the experience of a relative, who went through seven cycles of antibiotics in a bid to rid himself of the toxin-producing bacteria, prompted his initial interest in developing a microbiome-based treatment for the common healthcare-associated infection, which affects about half a million people in the US yearly.

“It’s really exciting to be in a position where we have strong evidence that we have options to help patients like him,” he said.

There were no serious side effects related to the treatment reported out of the trial.

Although the experimental treatment met the study’s main goal, the results weren’t quite strong enough to back up an FDA submission, Smith said. Based on its prior discussions with the agency, Finch will conduct another, larger trial to confirm the results before asking the FDA to review the pill.

The data were, however, good enough to prompt the company to start another program evaluating CP101: Finch now will also test the investigational drug as a treatment for chronic hepatitis B infection, the world’s most common blood-borne infection.

Jessica Allegretti, principal investigator on the trial, suggested the result “validates the approach of microbiome restoration.”

The company says it will present full results at an upcoming medical conference.

In addition to its lead drug candidate, which leverages a “full spectrum” of donor-derived microbiota, Finch is also working on developing drugs that deploy “rationally selected” assemblages of microorganisms with particular microbial strains from which it believes patients with certain conditions will most benefit. To find those, Smith says the company works backward from clinical data to identify especially helpful bacteria. Using that method, in partnership with Takeda Pharmaceutical (NYSE: TAK), it is advancing treatments intended to address ulcerative colitis and Crohn’s disease, both forms of inflammatory bowel disease.

A third approach the company is pursuing is a combination of its full-spectrum and rationally designed methods by adding into a donor-derived mix strains that aren’t ubiquitous in typical donors, but are believed to engage certain mechanisms associated with the disease. That’s the theory behind its preclinical program to develop a drug to reestablish a normal microbiome composition and function in children with autism spectrum disorder who suffer from gastrointestinal symptoms.

Finch’s efforts are supported by its latest funding round, a $53 million Series C financing that closed in August 2019. New investors including OCV Partners, Susquehanna International Group, Symbiosis, and the Trans-Pacific Technology Fund, and earlier investors participated.

Other companies are vying to be the first to win FDA approval of a microbiome-based therapy.

Neck-and-neck with Finch is Cambridge, MA-based Seres Therapeutics (NASDAQ: MCRB), which is also in late-stage testing with a microbiome therapy designed to treat recurrent C. diff. The company has said it plans to share its preliminary results in mid-2020, and that—like Finch—has talked with the FDA about potentially using that data to submit it for regulatory review, although it’s possible the agency will ask for additional information. The Seres trial, ECOSPOR III, is a Phase 3 study that enrolled 182 patients.