Full Press Release Details
Forward Looking Statements Some of the statements in this presentation
constitute "forward looking statements" under the Private Securities Litigation Reform Act of 1995, including, but not limited to the anticipated supply and degree of market acceptance of VOWST; the potential for microbiome therapeutics
to protect against infection; the timing of clinical development; our development opportunities and plans; the ultimate safety and efficacy data for our products; access to additional debt tranches; and other statements which are not historical
fact. Such statements are subject to important factors, risks and uncertainties, such as those discussed under the caption Risk Factors in the Company's Quarterly Report on Form 10-Q filed on May 9, 2023, and its other filings with the SEC,
that may cause actual results to differ materially from those expressed or implied by such forward looking statements. Any forward-looking statements included herein represent our views as of today only. We may update these statements, but we
disclaim any obligation to do so. 2 Seres Therapeutics, Inc. 2023
TM VOWST - First FDA Approved Orally Administered Commercially
Microbiota-Based Therapeutic available TM VOWST is indicated to prevent the recurrence of C. difficile infection (CDI) in individuals 18 years of age or older following antibacterial treatment for recurrent CDI (rCDI). Seres is pioneering a new
modality, led by VOWST 3 Seres Therapeutics, Inc. 2023
Seres Mission: Transforming the Lives of Patients Worldwide with
Revolutionary Microbiome Therapeutics Encapsulated consortia of commensal bacteria designed to target multiple disease-relevant pathways simultaneously Bacterial Consortia Orally-formulated, using current Good Disease Engraftment Restructure Change
in Change Manufacturing susceptible of drug microbiome microbiome in host Practices (cGMP) baseline microbiome species composition function function Other Bile acids Tryptophan metabolites Short-chain fatty acids 4 Seres Therapeutics, Inc.
Strategic Priorities | Expanding Microbiome Therapeutic Leadership FDA
approved on April 26, 2023; potential to transform management of recurrent Successfully commercialize C. difficile infection TM VOWST , first-in-class orally administered microbiome Commercially available therapeutic
Co-commercialization agreement with Nestl Health Science Ongoing SER-155 Phase 1b study in allo-HSCT* patients for prevention of bacterial infections and acute GvHD* Maximize opportunities in SER-155 Phase 1b Cohort 1 Day 100 data
support continued development Infection Protection Preclinical portfolio to prevent infection in medically compromised patients, including cancer neutropenia, cirrhosis and solid organ transplant Assessment of potential to
utilize biomarker-based patient selection in Ulcerative Colitis Continue research to inform underway further development in ulcerative colitis and SER-155 GvHD results may further inform path forward in immune modulation immune modulation *
allo-HSCT: allogeneic hematopoietic stem cell transplant; GvHD: graft versus host disease 5 Seres Therapeutics, Inc. 2023 SER-155 is an investigational microbiome therapeutic that has not been approved by any regulatory authority, including
the U.S. Food and Drug Administration (FDA)
VOWST is the First Approval from Our Pipeline of Oral Microbiome
Therapeutics INFECTION PROTECTION Preclinical Phase 1b Phase 2b Phase 3 FDA Approval Collaborators 1,2 VOWST Recurrent C. difficile (fecal microbiota spores, live-brpk) Bloodstream and antimicrobial-resistant bacterial infections & 3 Cohort 2 of
Phase 1b proceeding SER-155 GvHD in allogeneic hematopoietic stem cell transplant patients Programs targeting antimicrobial-resistant infections in medically compromised groups (e.g., cancer neutropenia, solid organ transplant) IMMUNE MODULATION 1 4
SER-287 Ulcerative colitis Research and assessment ongoing to determine future ulcerative colitis 1 development plans 4 SER-301 Ulcerative colitis Modulate host immunity/inflammation to improve Oncology response and tolerability of cancer treatments
Immunotherapy 1. Collaboration with Nestl Health Science, announced Jan. 11, 2016, regarding C. difficile and IBD programs for markets outside of North America. 2. VOWST co-commercialization agreement for North America with Nestl Health
Science announced July 1, 2021 3. SER-155 preclinical work was supported in part by CARB-X 6 Seres Therapeutics, Inc. 2023 4. No current clinical trials. Translational research activities are ongoing, informed by learnings from SER-287 Phase
2b and SER-301 Phase 1b study data, to evaluate the potential to utilize biomarker-based patient selection and stratification in future clinical development efforts
TM VOWST and Recurrent C. difficile Infection 7 Seres Therapeutics, Inc.
C. difficile Infections Are an Urgent Public Health Threat
Spore-forming, toxin- Symptoms include colitis Acute onset of severe High probability of producing, gram-positive, and severe, watery symptoms leads to recurrence >20%, usually anaerobic bacteria diarrhea with up to 15 hospitalization for within
1-2 weeks after bowel movements a day many patients completion of antibiotic therapy CLOSTRIDIOIDES 40-50% DIFFICILE 20,000+ ~156K Risk of recurrence escalates Recurrent CDI cases CDI deaths per year once a patient has an initial THREAT LEVEL
estimated for 2023 (U.S.) recurrence, which can trap URGENT patients in a vicious cycle (U.S.) 1. US CDC. Antibiotic Resistance Threats in the United States, 2019. US Department of Health and Human Services, CDC; 2019. doi:10.15620/cdc:82532 2.
Feuerstadt P et al. J Med Econ. 2020;23(6):603-609. 3. Chilton CH et al. Clin Microbiol Infect. 2017;24(5):476-482. 4. Ofosu A. Ann Gastroenterol. 2016;29(2):147-154. 5. Cole SA, Stahl TJ. Clin Colon Rectal Surg. 2015;28(2):65-69.
doi:10.1055/s-0035-1547333. 6. Wilcox MH et al. Open Forum Infect Dis. 2020;7(5):ofaa114. doi:10.1093/ofid/ofaa114 7. Centers for Disease Control and Prevention. Your risk of C. diff. Accessed January 28, 8 Seres Therapeutics, Inc. 2023 2022.
https://www.cdc.gov/cdiff/risk.html 8. Jiang ZD et al. Aliment Pharmacol Ther. 2017;45(7):899-908.9. McFarland LV et al. Am J Gastroenterol. 2002;97(7):1769-1775,
VOWST Offers an Attractive Product Profile Highlights of Prescribing
Information Broad product label covering adults with rCDI, including at Indication VOWST is indicated to prevent the recurrence of first recurrence statement Clostridioides difficile infection (CDI) in individuals 18 years of age and older
following antibiotic treatment for recurrent CDI (rCDI) Approximately 88% recurrence-free at 8 weeks* Limitations of use VOWST is not indicated for the treatment of CDI Well-tolerated in Phase 3 clinical studies. The most common
adverse reactions were mild to moderate in severity and transient in nature. Oral dosing - 4 capsules once daily for 3 consecutive days following antibiotic treatment and laxative No refrigeration requirements Full prescribing
information available at vowst.com Note: Sustained clinical response % is calculated as 100% minus % with recurrence 9 * Compared to 60% in the placebo arm Feuerstadt P et al. N Engl J Med. 2022;386(3):220-229.
VOWST is Highly Anticipated by Healthcare Professionals TM HCP Intent
to Prescribe VOWST Recurrent C. difficile infection is a highly " debilitating and life-threatening disease, and 22% antibiotics alone do not address the underlying Definitely will cause of rCDI, dysbiosis of the gut microbiome. ~75% The
approval of VOWST provides an important of surveyed HCPs new oral treatment option for this disease, and I definitely or probably am pleased to now be able offer this medicine 52% will prescribe to patients that have experienced a CDI Probably will
TM VOWST recurrence. " Dr. Carl Crawford, M.D. Assistant Professor of Clinical Medicine Division of Gastroenterology, Weill Cornell Medicine 25% Might or might not 1% Definitely or probably will not 10 Seres Therapeutics, Inc. 2023
Source: GI and ID survey (n=300), 2021
HCP Enthusiasm for VOWST Driven by Desire to Prevent Recurrences and
Limitations of Current Options Top 5 rCDI Treatment Goals Top 5 Unmet Needs % Ranked in Top 3 % Ranked in Top 3 Prevention of Preventing subsequent 59% 66% Prevention of recurrences is recurrences recurrences seen as a top treatment goal for
rCDI patients Prevention of Sustained efficacy / 48% 57% morbidity / mortality durability Despite it being the top goal, physicians perceive standard Restoring 38% 40% More affordable Tx of care as lacking efficacy at patient QoL preventing
recurrences Restore gut Symptom As a result, preventing 35% 34% microbiome relief recurrences is also the biggest unmet need leading to Restoration of gut More rapidly address 25% 29% heightened appetite for a microbiome symptoms product
like VOWST 11 Seres Therapeutics, Inc. 2023 Source: Seres physician survey data (2022)
Co-commercializing VOWST in the United States with 50/50 profit sharing
per July 2021 agreement, extending global strategic collaboration Combined Field Teams to Cover Highest Potential rCDI Prescribers Prioritize top volume and early adopting HCPs: Prioritize ~300 top HCOs: 20-person hospital team 150-person GI sales
force Includes ID engagement; ~1500 ID specialists see > 2 rCDI GI sales force covers 85% of GI practices for current patients/year inline Nestle product, ZENPEP Deployed Q1 23; profiled top institutions
Average 10 years industry experience & 5 years in GI Drove ZENPEP acceleration over last 3 years 12 Seres Therapeutics, Inc. 2023
Engaging with Key Commercial and Medicare Part D Plans to Initiate
Broad Coverage Path to coverage for VOWST Payer mix Up to Launch + 12 months Launch + 18 months Payers utilize NTMBs* to limit Medicare coverage 37% Medicare demand begins 54% Commercial Launch + 12 months 6% Medicaid VOWST Medicaid coverage Launch
begins 13 Seres Therapeutics, Inc. 2023 * New To Market Block (NTMB) deny insurance coverage of a new therapy until it can be reviewed and covered by the health plan.
VOWST Delivers Compelling Value Proposition We Are Committed to Broad
Patient Access Uniquely addresses #1 unmet need of preventing Addresses costly burden of rCDI: $43,000 cost / 1 recurrence, with robust efficacy, an established patient safety profile, and an orally administered regimen Innovative product; first and
only FDA- Commitment to patient access and affordability approved orally administered microbiota-based therapeutic Providing financial and treatment support for eligible patients* *Subject to specific eligibility and financial criteria 14 Seres
Therapeutics, Inc. 2023 Sources: 1. Rodrigues et al Infect Control Hosp Epidemiol. 2017 Feb;38(2):196-202. ; inflation adjusted from $34K in 2016 dollars to 2023 dollars
Laying the Foundations to Ultimately Transform Standard of Care Initial
Focus Expanded Focus Increase HCP awareness and Drive repeat use among higher- trial of an entirely new modality volume HCPs Provide positive experience Increase reach to lower-volume HCPs Enhance hospital
outflow Optimize payer coverage with a Engage payers to build coverage focus on commercial plans 15 Seres Therapeutics, Inc. 2023
Well Positioned to Supply Commercial Demand at Launch and Beyond 10+
years of Seres technology & facility investment for anaerobic bacterial therapeutics Seres in-house GMP Manufacturing and Quality Control High-quality CMO support TM VOWST commercial supply + Bacthera collaboration provides redundancy and
expands upon existing commercial supply capacity Joint venture between Chr. Hansen and Lonza with offices in Switzerland and Denmark Launch batches manufactured; anticipate Bacthera commercial drug production in 2024 for release in 2025, as the
expected number of patients treated expands 16 Seres Therapeutics, Inc. 2023 Note: Seres and Bacthera collaboration press release issued Nov. 10, 2021
SER-155 and Infection Protection Franchise 17 Seres Therapeutics, Inc.
Antimicrobial Resistant Infections - Urgent Public Health Threat Major
burden to society Many high-risk patient populations Declared "one of the Allogeneic HSCT recipients at risk for world's most urgent bloodstream infections threats" Additional patients with suppressed immune systems
(e.g., transplant $20 billion excess recipients, cancer patients) direct healthcare costs Patients with chronic diseases 35,000 deaths (e.g., cirrhosis) per year in US Limited innovation despite substantial and growing impact 18 Seres
Therapeutics, Inc. 2023
SER-155 Designed to Modulate Targets that Address Leading Causes of
Mortality Following Allogeneic HSCT (allo-HSCT) Investigational 16-strain cultivated bacterial Specifically designed to reduce infections and consortium optimized using MbTx platform GvHD in allo-HSCT recipients Organ Second failure Malignancy 1%
7-9% Infection 17-21% Primary Causes of allo-HSCT disease mortality at 1 year** GVHD 46-60% Consortium of unique, human commensal bacterial strains 19-23% Cultivated and encapsulated for oral delivery Strain selection based
on broad pre-clinical screening for defined functions and insights from microbiome clinical data Preclinical data show SER-155 leads to multi-log reductions of Allo-HSCT recipients are medically vulnerable; Enterococcus (including
VRE) and Enterobacteriaceae 50% 3 year mortality (including CRE) linked to GvHD in allo-HSCT patients* * Seres data shared in Jan 2022 Infection Protection Investor Event; VRE = vancomycin-resistant Enterococci; CRE = carbapenem-resistant
Enterobacterales; VRE and CRE both included in US CDC Antibiotic Resistance Threats 19 Se Seres T res The herap rapeu eutics, tics, Inc. Inc. 20 2023 23 ** CIBMTR 2020
SER-155 May Represent a Novel Solution to Reduce GI Pathogen Abundance
and Infection & GvHD in Allogeneic HSCT Oral, cultivated consortium, designed to reduce abundance of pathogens linked to infections and GvHD in allogeneic HSCT recipients* Enrollment ongoing in SER-155 Phase 1b study Cohort 1
SER-155 Phase 1b SER-155 well-tolerated through 100 Days post HSCT Cohort 2, a randomized, double-blind, placebo- SER-155 bacterial strain engraftment was as expected controlled study GI pathogen domination was rare and
transient in patients after SER-155 treatment compared to expected rates from prior cohort studies Expect Phase 1b Cohort 2 Topline Results in Mid-2024 *Note: SER-155 is an investigational therapeutic and has not been approved by any regulatory
authority, including the US Food & Drug Administration 20 Se Seres T res The herap rapeu eutics, tics, Inc. Inc. 20 2023 23
ESKAPE Pathogen Domination was Rare and Transient in Cohort 1 ESKAPE
pathogen domination* in SER-155 administered subjects observed at rates substantially lower than reference cohort SER-155 Cohort 1 Fig.1 Cumulative Domination Incidence From HSCT Day 0-30, 11% of patients (1 subject, Fig.1 blue line)
From HSCT day 0-100, 22% of patients (2 subjects, Reference Cohort Incidence 64% not shown) (459 subjects) All instances of pathogen domination were transient Reference Patient Cohort (MSKCC; Peled et al. 2020) Day 0 through 30, 64%
of patients (Fig.1 black line) Pathogen domination has been shown to be SER-155 Cohort-1 Incidence 11% associated with risk of blood stream infections (9 subjects) (Taur, CID 2012) and GvHD (Jenq Bio BMT 2015; Stein-Thoeringer Science 2019) * i.e.,
the families: Enterococcaceae, Enterobacteriaceae, Streptococcaceae & Staphylococcaceae HSCT Day 21 Se Seres T res The herap rapeu eutics, tics, Inc. Inc. 20 2023 23 Cumulative Incidence
SER-155 Potential Integration into Allogeneic HSCT Treatment Regimen
Unique potential clinical and economic value for allogeneic HSCT patients Substantial impact for patients: Favorable safety profile based on almost 30,000 transplants / year across Cohort 1 data suggests appropriate for US and Europe use across HSCT
population Avoids costs of post-transplant Double benefit of reducing infections and complications: $181K average additional GvHD, 2 of 3 leading causes of mortality costs for US patients with complications at 1 year Sources: CIBMTR 2020; Passweg et
al Bone Marrow Transplantation 57 (2022) 742-752; Perales et al Biol Blood Marrow Transplant 23 (2017) 1788-1794; Broder, et al. "The Cost of Hematopoietic Stem-Cell Transplantation in the United States" Am Health and Drug Benefits
10 (2017) 366-374; 22 Se Seres T res The herap rapeu eutics, tics, Inc. Inc. 20 2023 23
Seres' Path Forward 23 Seres Therapeutics, Inc. 2023
Maximizing the Opportunity in Infection Protection Broadly Target
Antimicrobial Resistant Broad preclinical Additional Opportunities Infections portfolio Driving to an additional clinical development program in 2023 Autologous HSCT Potentially 2+ Cancer Neutropenia Pre-clinical Portfolio
additional programs Solid Organ Transplant within 3 years Cirrhosis SER-155 Active Clinical SER-155: Development BSI & GvHD in allogeneic HSCT recipients Therapeutic adjacency to VOWST Phase 1b study ongoing in cohort 2 Now
Approved VOWST rCDI 24 Seres Therapeutics, Inc. 2023