Our Programs

Seres’ microbiome therapeutics represent an entirely new class of potential medicines with promise across a wide range of diseases.

INFECTION PROTECTION
Preclinical
Phase 1b
Phase 2b
Phase 3
FDA Approval
Collaborators
INFECTION PROTECTION
1,2

Product overview

SER-155 is an investigational, oral, rationally designed, fermented microbiome therapeutic designed to reduce the risk of gastrointestinal infections, bacteremia, and graft versus host disease (GvHD) in immunocompromised patients, including patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Mechanism of action

SER-155 is a multifunctional consortium of commensal bacteria designed based on human clinical insights. SER-155 is designed to augment the following microbiome functions, which are associated with better survival and lower rates of infection and GvHD in patients undergoing stem cell transplantation →

Unmet need in antibiotic-resistant infections and GvHD

Antibiotic-resistant infections, GvHD, and mortality are frequent, serious complications of organ or stem cell transplantation. Antibiotics used to treat infections in this patient population are not always effective and can have significant side effects. Current therapies for the prevention of GvHD rely on broad immunosuppression, which increases the risk of infection and has limited efficacy for a significant proportion of patients.

Status of clinical development

Phase I study now enrolling (ClincalTrials.gov Identifier: NCT04995653).

 
IMMUNE MODULATION
 
 
 
 
 
IMMUNE MODULATION
Research ongoing to determine future ulcerative colitis development plans
1
Research ongoing to determine future ulcerative colitis development plans
1

Scientific literature

Black R, et al. The burden of illness associated with recurrent Clostridioides difficile infection: a claims-based analysis. Presented at IDWeek 2021; October; Virtual.

Wilcox, et al. The efficacy and safety of fecal microbiota transplant for recurrent Clostridioides difficile infection: current understanding and gap analysis. Open Forum Infect. 2020;7(5):ofaa114. doi:10.1093/ofid/ofaa114

SER-109

Publications:

Feuerstadt P, Louie TJ, Lashner B, et al. SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection. N Engl J Med. 2022;386:220-9. DOI: 10.1056/NEJMoa2106516

McGovern BH, Ford CB, Henn MR, et al. SER-109, an investigational microbiome drug to reduce recurrence after Clostridioides difficile infection: lessons learned from a phase 2 trial. Clin Infect Dis. 2021;72(12):2132-2140. doi:10.1093/cid/ciaa387

Khanna S, Pardi DS, Kelly CR, et al. A novel microbiome therapeutic increases gut microbial diversity and prevents recurrent Clostridioides difficile infection. J Infect Dis. 2016;214(2):173-81. doi:10.1093/infdis/jiv766

Conference Talks and Posters:

Korman L, et al. Investigational Microbiome Therapeutic SER-109 Reduces the Risk of Recurrent Clostridioides difficile Infection (rCDI) Compared to Placebo in Patients with Risk Factors for Recurrence, Including Acid-Reducing Medications. Presented at: American College of Gastroenterology 2021; October; Las Vegas, NV.

Brown L, et al. Impact of SER 109, an Investigational Microbiome Therapeutic on Health-Related Quality of Life in Patients with Recurrent Clostridioides difficile Infection: Results from ECOSPOR III, a Placebo-Controlled Clinical Trial. Presented at: American College of Neuropsychopharmacology 2021; December; San Juan, PR.

Straub TJ, et al. SER-109, An Investigational Microbiome Therapeutic, Reduces Abundance of Antimicrobial Resistance Genes in Patients with Recurrent Clostridioides difficile Infection (rCDI). Presented at: 5th Annual Texas Medical Center Antimicrobial Resistance and Stewardship Conference 2022; January; virtual.

Amin A, et al. Incidence of hospitalizations in ECOSPOR III, a Phase 3, Double-Blind, Randomized Trial in Patients with Recurrent Clostridioides difficile Infection. Presented at: Society of Hospital Medicine 2022; April; Nashville, TN.

Cohen SH, Louie T, Sims M, et al. Investigational microbiome therapeutic SER-109 reduces recurrence of Clostridioides difficile infection (rCDI) compared to placebo, regardless of risk factors for recurrence. Presented at: IDWeek Conference 2021; October; virtual.

Hohmann E, Feuerstadt P, Oneto C, et al. The impact of investigational purified microbiome therapeutic SER-109 on health-related quality of life (HRQoL) of patients with recurrent Clostridioides difficile infection (rCDI) in ECOSPOR-III, a placebo-controlled clinical trial. Presented at: IDWeek Conference 2021; October; virtual.

Louie T, Sims M, Nathan R, et al. Time to recurrence of Clostridioides difficile infection (rCDI) is rapid following completion of standard of care antibiotics: results from ECOSPOR-III, a phase 3 double-blind, placebo-controlled randomized trial of SER-109, an investigational microbiome therapeutic. Presented at: IDWeek Conference 2021; October; virtual.

McChalicher C, Abdulaziz A, Halvorsen E, et al. Manufacturing Processes of SER-109, a purified investigational microbiome therapeutic, reduce risk of transmission of emerging and undetected infections in donor stool. Presented at: IDWeek Conference 2021; October; virtual.

Sims M, Khanna S, Pardi D, et al. Diagnostic testing among patients with suspected recurrent Clostridioides difficile infection (rCDI) in ECOSPOR-III a phase 3 clinical trial: implications for clinical practice vs clinical trials. Presented at: IDWeek Conference 2021; October; virtual.

Kraft CS, Lombardo MJ, Louie T, et al. Characterization of ribotypes among study participants in a phase 3 trial of investigational microbiome therapeutic SER-109 to reduce recurrent Clostridioides difficile infection (RCDI). Presented at: World Microbe Forum 2021; virtual.

Korman L, Lashner B, Kraft CS, et al. 24 week efficacy and safety data from Ecospor III: a phase 3 double blind, placebo controlled, randomized trial of SER-109, an investigational microbiome therapeutic for recurrent Clostridioides difficile infection. Presented at: Digestive Disease Week (DDW) 2021; May; virtual.

Bryant JA, Liyang D, O’Brien EJ, et al. Rapid conversion of primary to secondary bile acids in subjects with recurrent Clostridioides difficile infection (CDI) following SER-109, an investigational microbiome therapeutic. Presented at: Digestive Disease Week (DDW) 2021; May; virtual.

Fonte A, Berenson C, Korman L, et al. ECOSPOR-III: a phase 3 double blind, placebo controlled randomized trial of SER-109 an investigational microbiome therapeutic for treatment of recurrent Clostridioides difficile infection (RCDI). Presented at: Making a Difference in Infectious Diseases (MAD-ID) Annual Meeting 2021; May; virtual.

Berenson C, Korman L, Kraft CS, et al. ECOSPOR-III: a phase 3 double blind, placebo controlled randomized trial of SER-109 an investigational microbiome therapeutic for treatment of recurrent Clostridium difficile infection (RCDI). Presented at: Society of Hospital Medicine 2021; May; Virtual.

McGovern BH, Sims M, Lashner B, et al. Efficacy and safety of investigational microbe drug SER-109 for treatment of recurrent Clostridioides difficile infection (RCDI). Presented at: Society of Healthcare Epidemiology of America 2021; April; virtual.

Almomani SA, Button JE, Schuster BM, et al. Inactivation of vegetative bacteria during production of SER-109, a microbiome-based therapeutic for recurrent Clostridioides difficile infection. Presented at: ASM Microbe Conference 2016; June; Cambridge, MA.

O’Brien EJ, Henn MR. Comparisons of microbiomes from US and European populations suggest that SER-109 may have clinical utility in broad geographic locations for the treatment of patients with recurrent Clostridioides difficile infection. Presented at: 26th European Congress of Clinical Microbiology and Infectious Diseases 2016; April; Cambridge, MA.

Lombardo MJ, Vulic M, Ohsumi T, et al. Vancomycin-Resistant Enterococcal (VRE) titers diminish among patients with recurrent Clostridioides difficile infection after administration of SER-109, a novel microbiome agent. Presented at: IDWeek Conference 2015; October; Boston, MA.

Wortman JR, Lombardo MJ, Vulic M, et al. Engraftment of SER-109 Spores was rapid and durable in patients with recurrent Clostridioides difficile infection. Presented at: ICCAC Conference 2015; September; Boston, MA.

Gooley, et al. Reduced mortality after allogeneic hematopoietic cell transplantation. N Engl J Med. 2010;363(22):2091-2101. doi:1056/NEJMoa1004383

Gratwohl, et al. Hematopoietic stem cell transplantation: a global perspective. JAMA. 2010;303(16):1617-24. doi:1001/jama.2010.491

Microbiome and Infection/GvHD

Taur, et al. The effects of intestinal tract bacterial diversity on mortality following allogeneic hematopoietic stem cell transplantation. Blood. 2014;124(7):1174-1182. doi:10.1182/blood-2014-02-554725

Stein-Thoeringer, et al. Lactose drives enterococcus expansion to promote graft-versus-host disease. Science. 2019; 366;1143-1149. doi:10.1126/science.aax3760

Peled, et al. Microbiota as predictor of mortality in allogeneic hematopoietic-cell transplantation. N Engl J Med. 2020; 382:822-34. doi:1056/NEJMoa1900623

Conference Talks and Posters:

Halvorsen E, Vulić M, O’Brien E, et al. Design and preclinical characterization of SER-155, an investigational cultivated microbiome therapeutic to restore colonization resistance and prevent infection in patients undergoing Hematopoietic Stem Cell Transplantation (HSCT). Presented at: IDWeek Conference 2021; October; virtual.

Publications:

Henn, et al. A Phase 1b safety study of SER-287, a spore-based microbiome therapeutic, for active mild to moderate ulcerative colitis. Gastroenterology. 2021;160(1):115-127.e30. doi:10.1053/j.gastro.2020.07.048

Conference Talks and Posters:

Sartor & Wu. Roles for intestinal bacteria, viruses, and fungi in pathogenesis of inflammatory bowel diseases and therapeutic approaches. Gastroenterology. 2017;152(2):327-339.e4. doi:10.1053/j.gastro.2016.10.012

Lloyd-Price, et al. Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases. Nature. 2019;569(7758):655-662. doi:10.1038/s41586-019-1237-9

SER-287

Conference Talks and Posters:

Wortman JR. SER-287, an investigational microbiome therapeutic, induces widespread transcriptional changes related to clinical remission in a placebo-controlled, double-blind randomized trial (SERES-101) in patients with active mild-to-moderate ulcerative colitis. Presented at: Digestive Disease Week (DDW) 2019; May 18-21; San Diego, CA.

SER-301

Conference Talks and Posters:

Nelson T, Oka A, Liu Bo, et al. In vivo characterization of SER-301, a rationally designed investigational microbiome therapeutic for patients with active mild to moderate ulcerative colitis. Presented at: Digestive Disease Week (DDW) 2021; May 21-23; virtual.

Gopalakrisnan, et al. Gut microbiome modulates response to anti-pd-1 immunotherapy in melanoma patients. Science. 2018;359(6371):97-103. doi:10.1126/science.aan4236

Matson, et al. The commensal microbiome is associated with anti-pd-1 efficacy in metastatic melanoma patients. Science. 2018;359(6371):104-108. doi:10.1126/science.aao3290

Routy, et al. Gut microbiome influences efficacy of pd-1-based immunotherapy against epithelial tumors. Science. 2018;359(6371):91-97. doi:10.1126/science.aan3706

Microbiome therapeutics and immuno-oncology

Publications:

Gopalakrishnan, et al. Intervention strategies for microbial therapeutics in cancer immunotherapy. IOTECH. 2020; doi:10.1016/j.iotech.2020.05.001

Conference Talks and Posters:

Sceneay J, Srinivasan S, Desjardins C, et al. Leveraging gut microbiota networks to impact tumor immunotherapy Presented at: American Association for Cancer Research Conference 2019; May. Cambridge, MA.

Sceneay J, Srinivasan S, Halley K, et al. Leveraging gut microbiota to impact tumor immunotherapy Presented at: American Association for Cancer Research Conference 2018; April. Cambridge, MA.