Diabetes Insipidus, Neurogenic

- PHOENIX Study Did Not Meet Prespecified Primary or Secondary Endpoints - Data From 664-Participant Study Reinforce That AMX0035 is Generally Safe and Well-Tolerated - Within the Next Eight Weeks, Amylyx Will Continue to Engage With Regulatory Authorities and the ALS Community to Share Topline Data; Amylyx Will Share Plans for RELYVRIO/ALBRIOZA in ALS Which May Include Voluntarily Withdrawing RELYVRIO/ALBRIOZA From the Market - At This Time, RELYVRIO/ALBRIOZA Will Continue to be Available for People Living With ALS; Amylyx Has Voluntarily Decided to Pause Promotion; Related Patient Support Services Will Remain in Place - Studies With AMX0035 in Wolfram Syndrome (WS) and Progressive Supranuclear Palsy (PSP) to Continue Based on Data Supporting its Potential in These Diseases - Amylyx to Host Investor Conference Call Today, March 8, at 8:00 a.m. ET CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Amylyx Pharmaceuticals, Inc. (NASDAQ: AMLX) (“Amylyx” or the “Company”) today announced topline results from PHOENIX, a global, 48-week, randomized, placebo-controlled Phase 3 clinical trial of AMX0035 (sodium phenylbutyrate and taurursodiol [also known as ursodoxicoltaurine]; RELYVRIO® in the U.S., ALBRIOZA™ in Canada) in people living with amyotrophic lateral sclerosis (ALS). PHOENIX did not meet its primary endpoint of reaching statistical significance (p=0.667) as measured by change from baseline in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score at Week 48, nor was there statistical significance seen in secondary endpoints. Amylyx plans to present the data from PHOENIX at an upcoming medical meeting and will publish the results in a medical journal later this year. Amylyx will continue to engage with regulatory authorities and the broader ALS community, including ALS specialists and other multidisciplinary experts, people living with ALS, and advocates, to discuss the results from PHOENIX within the next eight weeks and make informed decisions. Amylyx intends to share plans for RELYVRIO/ALBRIOZA in ALS, which may include voluntarily withdrawing RELYVRIO/ALBRIOZA from the market. At this time, RELYVRIO/ALBRIOZA and its related patient support program will continue to be available for people living with ALS. Amylyx has voluntarily decided to pause promotion of the medication during this time. “We are surprised and deeply disappointed by the PHOENIX results following the positive data from the CENTAUR trial. Our main priority at the moment is sharing the information with people living with ALS and their treating physicians; this is part of our continued commitment to them and our mission. Over the next eight weeks, our team will continue to engage with regulatory authorities and the ALS community to discuss the results from PHOENIX. We will be led in our decisions by two key principles: doing what is right for people living with ALS, informed by regulatory authorities and the ALS community, and by what the science tells us. On behalf of the entire Amylyx team, we are grateful to the ALS community and for the dedication of trial participants, investigators, and study site teams. With data collected from 664 participants in PHOENIX, we are certain there will be important learnings that will help inform future ALS research. We are steadfast in our commitment to the ALS community and our mission, including with AMX0035 where it has shown potential in neurodegenerative diseases such as Wolfram syndrome and progressive supranuclear palsy, and with AMX0114, our investigational antisense oligonucleotide targeting calpain-2, in ALS,” said Justin Klee and Joshua Cohen, Co-CEOs of Amylyx. PHOENIX Study Results: The Phase 3 PHOENIX study enrolled 664 adults living with ALS. Participants were randomized three-to-two to receive either AMX0035 or placebo, with both treatment groups receiving standard-of-care. Continuation of a stable dosing regimen of riluzole and/or edaravone was permitted. PHOENIX did not meet the primary endpoint: There was no significant difference observed between participants treated with AMX0035 and placebo in ALSFRS-R total score change from baseline at Week 48 (p=0.667). No significant difference was observed in the subset of participants who met the CENTAUR trial criteria. There were also no significant differences observed across secondary endpoints. Consistent safety and tolerability profile: AMX0035 was well-tolerated in PHOENIX. There were no new safety signals, reinforcing the favorable and manageable safety pro with AMX0035 to date. European participants who completed the 48-week randomized phase had the option to enroll in an open label extension of the trial of up to two years in duration, which remains ongoing. Science of AMX0035: AMX0035, a specially formulated oral fixed-dose combination of PB and TURSO, has been shown in numerous preclinical studies to have a robust, synergistic effect in targeting two different destructive neurodegenerative disease pathways by mitigating endoplasmic reticulum stress and the associated unfolded protein response and mitochondrial dysfunction thereby reducing neuronal cell death. Additionally, AMX0035 has been shown to also reduce markers associated with neurodegenerative diseases in clinical trials, including a reduction of tau, a key protein aggregate shared across several neurodegenerative diseases, and YKL-40, a marker of neuroinflammation. Update on Ongoing AMX0035 Studies: The global, randomized, double-blind, placebo-controlled Phase 3 ORION clinical study of AMX0035 in PSP remains ongoing. The first participant was dosed in December 2023, and the Company is planning for an interim analysis. Topline results continue to be anticipated in 2025 or 2026. Data from the ongoing 12-participant, single site, open-label Phase 2 HELIOS clinical study are demonstrating evidence of clinical activity of AMX0035 in Wolfram syndrome. This study is fully recruited, and the Company plans to present preliminary data in the second quarter of 2024. Investor Conference Call Information Amylyx’ management team will host a live conference call and webcast today, March 8, 2024, at 8:00 a.m. ET to discuss the results of the PHOENIX trial. To participate in the conference call, please dial +1 (877) 870-4263 (U.S.), +1 (855) 669-9657 (Canada), or +1 (412) 317-0790 (International) at least 10 minutes prior to the start time and ask to be joined into the Amylyx Pharmaceuticals call. All interested parties are invited to access a live broadcast of the call via a webcast, which will be available on the “Events and Presentations” page in the “Investors” section of the Company’s website at investors.amylyx.com/news-events/events. An archived webcast will be available on the Company's website approximately two hours after the conference call and will be available for replay for 90 days following the call. About the PHOENIX Trial PHOENIX was a 48-week, randomized, placebo-controlled, global Phase 3 clinical trial further evaluating the safety and efficacy of AMX0035 (sodium phenylbutyrate and taurursodiol) for the treatment of ALS. The primary efficacy outcome of the trial was change from baseline in ALS Functional Rating Scale-Revised (ALSFRS-R) total score at 48 weeks. Secondary endpoints include quality of life patient-reported outcome assessments, overall survival, and respiratory function as measured by slow vital capacity (SVC). Safety and tolerability were also assessed. European participants who completed the 48-week trial had the option to enroll in an open-label extension (OLE) phase. During this phase, all participants receive AMX0035, and continued safety and efficacy measures will be assessed. About the CENTAUR Trial CENTAUR was a multicenter Phase 2 clinical trial in 137 participants with ALS encompassing a 6-month randomized, placebo-controlled phase and an open-label long-term follow-up phase. The trial met its primary efficacy endpoint of reducing functional decline as measured by the ALS Functional Rating Scale-Revised (ALSFRS-R). Overall, reported rates of adverse events and discontinuations were similar between AMX0035 and placebo groups during the 24-week randomized phase; however, gastrointestinal events occurred with greater frequency (≥2%) in the AMX0035 group. Detailed data from CENTAUR is published in the New England Journal of Medicine (NEJM) and Muscle & Nerve. The CENTAUR trial was funded, in part, by the ALS ACT grant and the ALS Ice Bucket Challenge, and was supported by The ALS Association, ALS Finding a Cure (a program of The Leandro P. Rizzuto Foundation), the Northeast ALS Consortium, and the Sean M. Healey & AMG Center for ALS at Mass General. About AMX0114 AMX0114 is an antisense oligonucleotide designed to target the gene encoding calpain-2, a key contributor to the axonal (Wallerian) degeneration pathway. Axonal degeneration has been recognized as an important early contributor to the clinical presentation and pathogenesis of ALS and other neurodegenerative diseases. Calpain-2 has been implicated in the pathogenesis of ALS based on findings of elevated levels of calpain-2 and its cleavage products in postmortem ALS tissue, therapeutic benefit of calpain-2 modulation in animal models of ALS, and the role of calpain-2 in cleaving neurofilament, a broadly researched biomarker in ALS. Preclinical studies completed to date have shown that AMX0114 achieves potent, dose-dependent, and durable knockdown of CAPN2 mRNA expression and calpain-2 protein levels in human motor neurons. Moreover, in preclinical efficacy studies, treatment with AMX0114 reduced extracellular neurofilament light chain levels following neurotoxic insult in iPSC-derived human motor neurons, and improved survival of iPSC-derived human motor neurons harboring ALS-linked, pathogenic TDP-43 mutations. About ALS Amyotrophic lateral sclerosis (ALS, also known as motor neuron disease) is a relentlessly progressive and fatal neurodegenerative disorder caused by motor neuron death in the brain and spinal cord. Motor neuron loss in ALS leads to deteriorating muscle function, the inability to move and speak, respiratory paralysis, and eventually, death. More than 90% of people with ALS have sporadic disease, showing no clear family history. ALS affects around 30,000 people in the U.S., and more than 30,000 people are estimated to be living with ALS in Europe (European Union and United Kingdom). People living with ALS have a median survival of approximately two years from diagnosis. About HELIOS The HELIOS trial (NCT05676034) is a 12-participant, open-label proof of biology, Phase 2 trial designed to study the effect of AMX0035 on safety and tolerability, and various measures of endocrinological, neurological, and ophthalmologic function in adult participants living with Wolfram syndrome (WS). About Wolfram Syndrome Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disease characterized by childhood-onset diabetes, optic nerve atrophy, and neurodegeneration. Common manifestations of WS include diabetes mellitus, optic nerve atrophy, central diabetes insipidus, sensorineural deafness, neurogenic bladder, and progressive neurologic difficulties. Genetic and experimental evidence suggest that endoplasmic reticulum (ER) dysfunction is a critical pathogenic component of WS. The prognosis of WS is poor, and many people with the disease die prematurely with severe neurological disabilities. About the ORION Trial The Phase 3 ORION trial (NCT06122662) is a global, randomized, double-blind, placebo-controlled Phase 3 clinical trial designed to assess the efficacy, safety, and tolerability of AMX0035 compared to placebo in people living with progressive supranuclear palsy (PSP). The ORION Phase 3 trial was designed and planned in collaboration with key global academic leaders, people living with PSP and their caregivers, and industry advocacy organizations. About PSP Progressive supranuclear palsy (PSP) is a sporadic, rare and adult-onset neurodegenerative disorder that affects walking and balance, eye movement, swallowing, and speech. People living with PSP have a life expectancy of six to eight years after initial diagnosis, and its epidemiology is similar to that of amyotrophic lateral sclerosis (ALS). PSP typically begins in late-middle age and rapidly progresses over time. The disease affects approximately seven in 100,000 people worldwide, and there are currently no disease-modifying therapies approved for the treatment of PSP. PSP is characterized by abnormal tau inclusions and is consequently also known as a tauopathy. Similar to other neurodegenerative diseases, pathophysiologic changes underlying PSP are multifactorial with several genetic and environmental factors likely contributing to tau dysfunction and aggregation. Multiple pathways, including genetic mutations, endoplasmic reticulum (ER) stress and the activation of unfolded protein response, mitochondrial dysfunction, and neuroinflammation have been implicated as contributors to tau dysfunction and aggregation. About AMX0035 / RELYVRIO® / ALBRIOZA™ AMX0035 is an oral, fixed-dose combination of sodium phenylbutyrate and taurursodiol (known as ursodoxicoltaurine outside of the U.S.). It is approved as RELYVRIO® to treat amyotrophic lateral sclerosis (ALS) in adults in the U.S. and approved with conditions as ALBRIOZA™ for the treatment of ALS in Canada. AMX0035 is being studied for the potential treatment of other neurodegenerative diseases, and Amylyx is exploring its treatment in other populations and regions. The formulation of RELYVRIO, ALBRIOZA, and AMX0035 is identical. RELYVRIO® (sodium phenylbutyrate and taurursodiol) Safety Information for United States WARNINGS AND PRECAUTIONS Risk in Patients with Enterohepatic Circulation Disorders, Pancreatic Disorders, or Intestinal Disorders RELYVRIO contains taurursodiol, which is a bile acid. In patients with disorders that interfere with bile acid circulation, there may be an increased risk for worsening diarrhea, and patients should be monitored appropriately for this adverse reaction. Pancreatic insufficiency, intestinal malabsorption, or intestinal diseases that may alter the concentration of bile acids may also lead to decreased absorption of either of the components of RELYVRIO. Because different enterohepatic circulation, pancreatic, and intestinal disorders have varying degrees of severity, consider consulting with a specialist. Patients with disorders of enterohepatic circulation (e.g., biliary infection, active cholecystitis), severe pancreatic disorders (e.g., pancreatitis), and intestinal disorders that may alter concentrations of bile acids (e.g., ileal resection, regional ileitis) were excluded from the study; therefore, there is no clinical experience in these conditions. Use in Patients Sensitive to High Sodium Intake RELYVRIO has a high salt content. Each initial daily dosage of 1 packet contains 464 mg of sodium; each maintenance dosage of 2 packets daily contains 928 mg of sodium. In patients sensitive to salt intake (e.g., those with heart failure, hypertension, or renal impairment), consider the amount of daily sodium intake in each dose of RELYVRIO and monitor appropriately. ADVERSE REACTIONS The most common adverse reactions (at least 15% and at least 5% greater than placebo) with RELYVRIO were diarrhea, abdominal pain, nausea, and upper respiratory tract infection. Gastrointestinal-related adverse reactions occurred throughout the study but were more frequent during the first 3 weeks of treatment. Please click here for RELYVRIO Full U.S. Prescribing Information. About Amylyx Pharmaceuticals Amylyx Pharmaceuticals, Inc. is committed to supporting and creating more moments for the neurodegenerative disease community through the discovery and development of innovative new treatments. Amylyx is headquartered in Cambridge, Massachusetts and has operations in Canada, EMEA, and Japan. For more information, visit amylyx.com and follow us on LinkedIn and X, (formerly Twitter). For investors, please visit investors.amylyx.com. Forward-Looking Statements Statements contained in this press release and related comments in our earnings conference call regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, Amylyx’ expectations regarding: interactions with regulatory authorities; the continued availability of RELYVRIO/ALBRIOZA for people living with ALS while such interactions are ongoing; the pausing of promotion of RELYVRIO/ALBRIOZA; pathways for continued access for patients if RELYVRIO/ALBRIOZA are withdrawn from the market; the possibility for Amylyx to voluntarily withdraw RELYVRIO/ALBRIOZA from the market; the continued evaluation of AMX0035 in other neurodegenerative diseases, including the timing for expected data readouts in the ORION and HELIOS studies; and the evidence of biological activity of AMX0035 in Wolfram syndrome. Any forward-looking statements in this press release and related comments in the Company's conference call are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include the risks and uncertainties set forth in Amylyx’ United States Securities and Exchange Commission (SEC) filings, including Amylyx’ Annual Report on Form 10-K for the year ended December 31, 2023, and subsequent filings with the SEC. All forward-looking statements contained in this press release and related comments in our conference call speak only as of the date on which they were made. Amylyx undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

CAMBRIDGE, Mass.--( BUSINESS WIRE )-- Amylyx Pharmaceuticals, Inc. (NASDAQ: AMLX) (“Amylyx” or the “Company”) today announced it has completed enrollment of its Phase 2 HELIOS trial of AMX0035 (sodium phenylbutyrate [PB] and taurursodiol [TURSO]) for the treatment of Wolfram syndrome (WS), a rare genetic disease that typically results in neurodegeneration and premature death, which has no known cure. The trial has enrolled 12 adult participants living with WS, and preliminary results are anticipated in the second half of 2024. “The unmet need for people living with WS remains significant. WS is progressive, often fatal, and difficult to diagnose, with current treatments focused mostly on helping to address symptoms,” said Fumihiko Urano, MD, PhD, Principal Investigator of the HELIOS clinical trial and Professor of Medicine in the Division of Endocrinology, Metabolism & Lipid Research at Washington University School of Medicine. “Our preclinical findings showed that AMX0035 may impact relevant WS disease pathways and manifestations, and we look forward to the preliminary results from HELIOS anticipated later this year.” HELIOS is an open-label proof of biology trial designed to study the effect of AMX0035 on safety and tolerability, and various measures of endocrinological, neurological, and ophthalmologic function in adult participants living with WS. Data from this initial study will inform potential future Amylyx trials for individuals with WS. More information on the HELIOS clinical study can be found at www.clinicaltrials.gov , NCT05676034. In September 2022, researchers from Washington University School of Medicine in St. Louis, in collaboration with Amylyx, published preclinical data in the peer-reviewed Journal of Clinical Investigation Insight . The data explored the potential of AMX0035 as a novel therapeutic approach for WS and provided initial proof-of-concept for its therapeutic development in WS. “Little progress has been made in the treatment of WS, and we are excited by the potential we have been seeing in the preclinical work with AMX0035,” said Camille L. Bedrosian, MD, Chief Medical Officer of Amylyx. “These preclinical findings suggest the possibilities of AMX0035 for individuals with WS that we continue to explore, including in the HELIOS trial. We are grateful to those who partnered to complete this important clinical trial enrollment milestone, in particular, the WS community, their families and caregivers, experts, clinicians, researchers, and advocacy leaders.” Amylyx announced that the FDA granted orphan drug designation to AMX0035 for the treatment of WS in November 2020. The FDA may grant this designation to drugs and biologics intended to treat a rare disease or condition affecting fewer than 200,000 persons in the U.S. Orphan designation qualifies a company for certain benefits, including financial incentives to support clinical development and the potential for seven years of market exclusivity in the U.S. upon regulatory approval. About Wolfram Syndrome Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disease characterized by childhood-onset diabetes, optic nerve atrophy, and neurodegeneration. Common manifestations of WS include diabetes mellitus, optic nerve atrophy, central diabetes insipidus, sensorineural deafness, neurogenic bladder, and progressive neurologic difficulties. Genetic and experimental evidence suggest that endoplasmic reticulum (ER) dysfunction is a critical pathogenic component of WS. The prognosis of WS is poor, and many people with the disease die prematurely with severe neurological disabilities. About AMX0035 / RELYVRIO ® / ALBRIOZA™ / ALBRIOZA ® AMX0035 is an oral, fixed-dose combination of sodium phenylbutyrate and taurursodiol (known as ursodoxicoltaurine outside of the U.S.). It is approved as RELYVRIO ® to treat amyotrophic lateral sclerosis (ALS) in adults in the U.S. and approved with conditions as ALBRIOZA™ for the treatment of ALS in Canada. AMX0035 is being studied for the potential treatment of other neurodegenerative diseases, and Amylyx is exploring its treatment in other populations and regions. The formulation of RELYVRIO, ALBRIOZA, and AMX0035 is identical. About Amylyx Pharmaceuticals Amylyx Pharmaceuticals, Inc. is committed to supporting and creating more moments for the neurodegenerative community through the discovery and development of innovative new treatments. Amylyx is headquartered in Cambridge, Massachusetts and has operations in Canada, EMEA, and Japan. For more information, visit amylyx.com and follow us on LinkedIn and X , formerly known as Twitter. For investors, please visit investors.amylyx.com . Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, the potential of AMX0035 as a treatment for ALS and the Company’s plans to explore the use of AMX0035 for other neurodegenerative diseases including Wolfram Syndrome, the timelines for the HELIOS study in WS, and expectations regarding our longer-term strategy. Any forward-looking statements in this press release are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include: Amylyx’ ability to fund operations, the success, cost, and timing of Amylyx’ program development activities, Amylyx’ ability to execute on its commercial and regulatory strategy, regulatory developments, expectations regarding the timing and outcome of EMA’s review of AMX0035 for the treatment of ALS, Amylyx’ reliance on third parties, including to conduct clinical trials and manufacture products, and the effect of global economic uncertainty and financial market volatility caused by economic effects of rising inflation and interest rates, the COVID-19 pandemic, geopolitical instability, changes in international trade relationships and military conflicts, as well as the risks and uncertainties set forth in Amylyx’ United States Securities and Exchange Commission (SEC) filings, including Amylyx’ Quarterly Report on Form 10-Q for the quarter ended September 30, 2023, and subsequent filings with the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Subject to any obligations under applicable law, Amylyx undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

VOWST preliminary net sales of approximately $10.4 million (unaudited) for the fourth quarter of 2023 Significant adoption of VOWST since commercial launch in June 2023 through year-end 2023 with 2,833 patient enrollment forms received and 2,015 new patient starts SER-155 Phase 1b placebo-controlled Cohort 2 data readout anticipated in third quarter of 2024 Seres to Present at 42nd Annual J.P. Morgan Healthcare Conference on January 10, 2024 CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Seres Therapeutics, Inc. (Nasdaq: MCRB), a leading microbiome therapeutics company, today announced preliminary key VOWST (fecal microbiota spores, live-brpk) launch metrics and receipt of US FDA Fast Track Designation for SER-155 ahead of its presentation at the 42nd Annual J.P. Morgan Healthcare Conference on Wednesday, January 10th. VOWST, the first FDA approved orally administered microbiome therapeutic, received FDA approval in April of 2023 and is indicated to prevent the recurrence of Clostridioides difficile infection (CDI) in adults following antibacterial treatment for recurrent CDI (rCDI). VOWST is being commercialized by Nestlé Health Science in collaboration with Seres. SER-155 builds upon the clinical success of VOWST and is an investigational oral, cultivated microbiome therapeutic designed to prevent GI-associated bacterial infections, including blood stream infections, and to reduce the incidence of severe acute graft-versus-host disease (GvHD) in immunocompromised patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). “In 2023, VOWST received FDA approval with a broad indication, which includes use in first recurrence patients. We are thrilled, along with our collaborators at Nestlé Health Science, to help patients exit the vicious cycle of recurrence that happens far too often with CDI,” said Eric Shaff, President and Chief Executive Officer at Seres. “The strong adoption of VOWST since launch is indicative of the high unmet need in this category, the highly compelling clinical pro VOWST, and the early success we have demonstrated in educating healthcare providers, payers and patients about this new treatment option.” “Seres is looking forward to 2024 as we continue to build on our initial VOWST commercial success. The SER-155 Cohort-2 readout is expected in the third quarter, and we are excited to announce receipt of Fast Track Designation for SER-155 to reduce the risk of infection and GvHD in allo-HSCT patients. Fast Track Designation is awarded to expedite both drug development and FDA review of drugs to treat serious conditions and fulfill an unmet medical need.” “I’m pleased with the significant progress made on our launch priorities since the commercial availability of VOWST in June,” said Terri Young, Ph.D., Chief Commercial and Strategy Officer at Seres. “Healthcare provider education efforts have scaled creating a positive customer experience with faster and higher conversion of enrollments to new patient starts. We look forward to continuing our efforts in 2024 with Nestlé Health Science and expect to make significant progress increasing the adoption of VOWST and achieving additional payer coverage.” Seres will present at the 42nd annual J.P. Morgan Healthcare Conference on Wednesday, January 10, 2024, at 12:45 pm ET / 9:45 am PT. The live presentation and archived webcast will be accessible from the company’s website at . VOWST Commercial Performance Broad demand for VOWST has been observed across rCDI patients and healthcare providers since product launch in June 2023: Fourth quarter net sales were approximately $10.4 million (unaudited) and reflected a gross-to-net reduction of 11%. Total 2023 net sales since launch in June were approximately $19.6 million (unaudited) and reflected a gross-to-net reduction of 13%. Fourth quarter completed prescription enrollment forms received for VOWST were 1,322; of those 1,082 resulted in new patient starts by year-end 2023. Total 2023 completed prescription enrollment forms received for VOWST since launch were 2,833; of those 2,015 resulted in new patient starts by year-end 2023. In 2023, prescription enrollment forms were submitted by approximately 1,330 unique healthcare providers (HCPs) since launch; approximately 340 HCPs have prescribed VOWST to more than one patient. Seres 2023 Highlights VOWST received FDA approval in April as the first and only FDA approved orally administered microbiome therapeutic to prevent recurrence of CDI in patients with rCDI, after treatment with standard of care antibacterials. Strong adoption of VOWST since commercial launch in June 2023 with broad utilization, continued quarter over quarter growth, and significant progress achieving patient access. Production of VOWST commercial supply enabled a strong commercial launch within weeks of approval; progress in expansion of VOWST manufacturing capacity. SER-155 Phase 1b Cohort 1 clinical data showed favorable tolerability, successful drug bacteria engraftment, and a substantial reduction in pathogen domination in the gastrointestinal microbiome supporting progression to the placebo-controlled Cohort 2. SER-155 received US FDA Fast Track Designation. Completed strategic restructuring of Company to focus resources and investment on continued VOWST growth, completion of SER-155 Phase 1b study and supporting longer-term business sustainability. Named to “TIME 100 Most Influential Companies” list of 100 companies making an extraordinary impact around the world. Anticipated 2024 Milestones Expect continued progress in 2024 towards commercial priorities including: Expansion of the number of HCPs prescribing VOWST as a result of new efforts scaled in Q4 2023 such as strengthened promotional campaigns and expanded reach of HCP and patient digital promotion. Growth of VOWST utilization earlier in the treatment paradigm including in patients experiencing their first recurrence. Maintenance of strong patient access and expansion of payer coverage for VOWST across Commercial and Medicare Part D plans. Increasing penetration of the hospital outflow patient segment. SER-155 Phase 1b placebo-controlled Cohort 2 data readout anticipated in third quarter of 2024. Seres ended 2023 with preliminary cash, cash equivalents and investments of approximately $128 million (unaudited). Seres anticipates that this year-end cash balance, in conjunction with the anticipated savings from the restructuring announced in November 2023 and the expected receipt of the $45 million Tranche B under its existing senior secured debt facility (the Term Loan Facility) with Oaktree Capital Management, L.P. (Oaktree), will support its operations into the fourth quarter of 2024. INDICATION AND IMPORTANT SAFETY INFORMATION FOR VOWST INDICATION VOWST is indicated to prevent the recurrence of Clostridioides difficile infection (CDI) in individuals 18 years of age and older following antibacterial treatment for recurrent CDI. Limitation of Use: VOWST is not indicated for treatment of CDI. IMPORTANT SAFETY INFORMATION WARNINGS AND PRECAUTIONS Transmissible infectious agents: Because VOWST is manufactured from human fecal matter, it may carry a risk of transmitting infectious agents. Report any infection that is suspected to have been transmitted by VOWST to Aimmune Therapeutics, Inc. at 1-833-246-2566. Potential presence of food allergens: VOWST may contain food allergens. The potential to cause adverse reactions due to food allergens is unknown. ADVERSE REACTIONS The most common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%), and diarrhea (10.0%). To report SUSPECTED ADVERSE REACTIONS, contact Aimmune Therapeutics at 1-833-AIM-2KNO (1-833-246-2566), or the FDA at 1-800-FDA-1088, or visit . DRUG INTERACTIONS Do not administer antibacterials concurrently with VOWST. Please see Full Prescribing Information and Patient Information About Seres Therapeutics Seres Therapeutics, Inc. (Nasdaq: MCRB) is a commercial-stage company developing novel microbiome therapeutics for serious diseases. Seres’ lead program, VOWST™, obtained U.S. FDA approval in April 2023 as the first orally administered microbiome therapeutic to prevent recurrence of C. difficile infection (CDI) in adults following antibacterial treatment for recurrent CDI and is being commercialized in collaboration with Nestlé Health Science. Seres is evaluating SER-155 in a Phase 1b study in patients receiving allogeneic hematopoietic stem cell transplantation. For more information, please visit . Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including the commercial success and continued growth of VOWST, the timing and results of our clinical studies, access to additional debt tranches, the sufficiency of cash to fund operations, and other statements which are not historical fact. These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: we have incurred significant losses, are not currently profitable and may never become profitable; our need for additional funding; our limited operating history; our novel approach to therapeutic intervention; our reliance on third parties and collaborators to conduct our clinical trials, manufacture our product or product candidates and develop and commercialize our product or product candidates, if approved; the unknown degree and competing factors of market acceptance for VOWST; the competition we will face; our ability to protect our intellectual property; and our ability to retain key personnel and to manage our growth. These and other important factors discussed under the caption “Risk Factors” in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC), on November 2, 2023, and our other reports filed with the SEC could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.