Nonliving microbe may be effective, safe oral treatment for psoriasis

A drug comprised of a nonliving single strain commensal microbe showed signs of safe and effective treatment of mild to moderate psoriasis, according to a presentation at the European Academy of Dermatology and Venereology virtual congress.

“EDP1815 is a nonlive pharmaceutical preparation of a bacteria called Prevotella histicola that lives within us all within our gut,” Douglas Maslin, MD, senior director, immunology clinical lead at Evelo Biosciences, told Healio. “When we take it, it goes into our small intestine, and rather than affecting the microbiome or colonizing our gut, it interacts with immune cells, which then go around the body and alter the inflammation that’s in our bodies.”

The phase 1b first-in-human clinical trial data of EDP1815 (Evelo Biosciences) included two cohorts of patients randomly assigned 2:1 to receive active drug or placebo. Patients received 1.6 × 10¹¹ bacterial cells or 8 × 10¹¹ cells of freeze-dried powder in enteric capsules for 28 days or placebo.

Both active treatment cohorts had a reduction in Psoriasis Area and Severity Index of 16% at day 28 compared with 1% in the placebo arm. After 42 days of follow-up, the higher-dose group had a 21% improvement from baseline compared with 10% in the lower-dose group and 3% in the placebo group.

“This is a completely new type of treatment. It’s not like anything else you’ll hear about,” Maslin said.

The drug is not absorbed into the body, allowing it to be used without interacting with other medications, and has the possibility to have an effect on multiple forms of inflammation.

“It is often not appreciated that the small intestine is the largest sensory organ in the body, sensing what passes into it from the external world and subsequently relaying immunomodulatory messages throughout the rest of the body,” Maslin said in his presentation. “This is essentially a topical drug administered to the small intestine.”

While the current trial is evaluating the effects on TH17 inflammation and psoriasis, EDP1815 has also shown pre-trial efficacy in TH2 and TH1 inflammation and is being studied for the treatment of COVID-19.

“I think there’s a real unmet need for a lot of dermatology patients, not just psoriasis but other inflammatory diseases as well,” Maslin told Healio. “To have something that’s potentially safe for these patients is big.”