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New evidence shows microbe strain can orally treat systemic inflammation in psoriasis

New evidence shows that systemic inflammation in psoriasis can be treated orally with a non-living strain of a commensal microbe

Say Communications

Research News

LUGANO, 29 October, 2020 - Disruptive innovations in psoriasis are leading the way at EADV's 29th Congress, EADV Virtual. New data published today shows the first clinical evidence of modulating systemic inflammation by oral delivery of a non-living single strain commensal microbe. This new therapeutic class brings hope for a completely new way of treating this debilitating skin condition (1).

The phase 1b clinical study, by Evelo Biosciences, evaluated EDP1815, a preparation of a non-living single strain of the bacterium Prevotella histicola, isolated from the small intestine of a human donor, in two cohorts of 12 and 18 patients with mild to moderate psoriasis for 28 days, with follow-up off treatment through 42 days. EDP1815 is an orally-delivered investigational therapy that is being developed for treatment of inflammatory diseases but has never been used for a human disease before.

The small intestine plays a central role in governing the body's immune, metabolic and neurological systems. When the oral microbe is administered, it interacts with a network of connections between the small intestine and the rest of the body, creating a systemic therapeutic immune response, without being absorbed into the body. This physiological mechanism of control has not been shown to cause any immune suppression, further reducing the risk of side-effects such as infections.

Early results showed that EDP1815 was well tolerated at daily doses of up to 8.0x101 cells administered for up to 28 days, with a tolerability profile comparable to placebo, with no serious adverse effects reported. At day 28, the mean percentage reduction in Psoriasis Area Severity Index (PASI) score for both EDP1815 cohorts was 16%, compared to 1% for placebo; with a further improvement to 21% in the high-dose cohort at day 42, but not the low dose cohort (10%) or placebo cohorts (3%). This is indicative of sustained and ongoing clinical effect at the higher dose. The mean reduction in Lesion Severity Scores (LSS) at 28 days were 15% and 23% in the high- and low-dose cohorts, respectively, compared to a 1% increase from baseline in the placebo group. Again, further clinical improvement, to a 24% reduction, was seen in the high-dose cohort.

Dr Douglas Maslin, Dermatologist and Pharmacologist at Addenbrooke's Hospital in Cambridge, UK working on secondment with Evelo Biosciences explains: "Although several treatments options are available for psoriasis patients with the most severe disease, there is a great need for new innovative methods for those living with mild-moderate disease. I decided to work with Evelo Biosciences after seeing the huge potential in EDP1815 and its oral mechanism of action. It is a real breakthrough, especially as we have seen from the pre-clinical and phase I trials that it was well tolerated with no overall difference from placebo and with no severe side effects reported. We are extremely encouraged to see that these data support further clinical development of EDP1815 in psoriasis. We are already in phase II clinical trials across the UK, Poland and US. This is a potentially massive win for the majority of psoriasis patients, as it has the potential to improve treatment options and perhaps change the current standard of care."

New guidelines and promising treatments in psoriasis at EADV Virtual

This year's EADV Virtual, which launches on World Psoriasis Day, will showcase some of the cutting-edge innovations and trends in psoriasis and key updates in the field. Today, this includes a presentation from Professor Dr Rolland Gyulai from Hungary, who will be sharing the new 2020 European and US guidelines and discussing the latest clinical trials and where there is still a place for classical systemic treatments (2).

Also, Associate Professor Eniko Sonkoly from the Department of Medicine Solna, Karolinska Institute/ Karolinska University Hospital Solna in Sweden, will be presenting a review of the existing and upcoming pipeline of small molecules that show great potential in managing and treating the condition (3). Professor Sonkoly explains: "Although there are many effective biologics, they are not suitable for all patients with psoriasis. There is a need for new oral and topical treatments with favourable safety profiles that can benefit mild, moderate and severe patients, improving their quality of life. Small molecules have the advantage of being suitable for both oral and topical delivery and have the potential to improve available treatment options."


Notes to Editors

A reference to the 29th European Academy of Dermatology and Venereology (EADV) Congress, EADV Virtual, or EADV Virtual 2020 must be included when communicating any information within this press release.


For further information or to arrange an expert interview, please contact or:

Lewis Picton - EADV Press Officer
+44 (0) 208 971 6419

Nina Vadjaraganian - EADV Press Officer
+44 (0) 208 971 6408

Sophie Graham - EADV Press Officer
+44 (0) 208 971 6413

About Psoriasis

Psoriasis is a chronic, systemic immune-mediated inflammatory disease that causes raised plaques and scales on the skin's surface (4). It can range in severity from a few scattered red, scaly plaques, to the involvement of almost the entire body surface - it may also wax and wane in its severity over time (5). There are many different kinds of psoriasis, but the most common is plaque psoriasis which is found in 80% of people with the condition (6). Psoriasis affects between 2-3% of the worlds' adult population, and <1% of children (7)(8)(9).

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About EDP1815:

EDP1815 is a non-living pharmaceutical preparation of a single strain of Prevotella histicola isolated from the duodenum of a human donor. It has potent anti-inflammatory effects on human immune cells in vitro and mouse models in vivo. Preclinically, EDP1815 systemically down-regulates multiple cytokines including TNF, IL-4, IL-6 and IL-17, without suppressing type 1 interferons. These effects are dependent on IL-10 signalling and are associated with increased epithelial expression of FoxP3. EDP1815 acts on the small intestinal axis, the network of connections between the small intestine and the rest of the body. It elicits systemic therapeutic effects without systemic absorption or modification of the microbiome. Epithelial and dendritic cells in the small intestinal mucosa continuously sample the contents of the lumen. Once exposed to EDP1815 these cells modulate inflammation systemically via cytokine signalling and T-cell trafficking. EDP1815 significantly reduced Th1, Th2 and Th17 inflammation in preclinical mouse models including keyhole limpet haemocyanin delayed-type hypersensitivity, MC903 model of allergic dermatitis, imiquimod-induced skin inflammation, and experimental autoimmune encephalomyelitis.

About EADV:

Founded in 1987, EADV is the leading community to further the knowledge of health professionals and advocates in the field of dermatology and venereology. It is a non-profit organisation with over 7,000 members, across 113 different countries in the world, providing a valuable service for every type of dermato-venereologist professional. The EADV is committed to improving the quality of patient care, continuing medical education for all dermato-venereologists within Europe and beyond, and advocacy on behalf of the speciality and patients. To find out more visit

About EADV Virtual:

This year's Congress is a first in EADV's history. EADV Virtual - New Frontiers in Dermatology and Venereology provides an exceptional opportunity for colleagues from around the world to explore the latest developments in science and patient care that are at the heart of the academy's mission. The user experience is immersive and simple to follow. To find out more visit


(2) Gyulai R. When to use classical systemic treatment, EADV Virtual, 29 October 2020. Inflammatory diseases: Psoriasis session, 11:15-11:30:
(3) Sonkoly E. Existing and upcoming small molecules, EADV Virtual, 29 October 2020. Inflammatory diseases: Psoriasis session, 12;00-12:15
(4) About Psoriasis. Available from: Accessed October 2020
(5) Paris R, et al. (2013) Global Epidemiology of Psoriasis: A Systematic Review of Incidence and Prevalence. Journal of Investigative Dermatology. 133(2):377-385.
(6) About Psoriasis. Available from: Accessed October 2020
(7) EADV. Information leaflet for patients. Psoriasis, a closer look. Available from: Accessed October 2020
(8) Psoriasis statistics. Available from:,125%20million%20people%20worldwide%E2%80%942%20to%203%20percent%20of%20the,the%20World%20Psoriasis%20Day%20consortium Accessed October 2020
(9) Global psoriasis atlas. Available from: Accessed October 2020

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