Seres Therapeutics Announces Leadership Transition
Seres Therapeutics (NASDAQ:MCRB) announced a significant leadership transition as Thomas DesRosier and Marella Thorell are appointed co-CEOs, effective July 31, 2025, following current CEO Eric Shaff's departure. Both executives will retain their existing roles as Chief Legal Officer and Chief Financial Officer, respectively.
The company is actively engaging with multiple parties for potential business development and partnerships to secure additional capital for advancing SER-155, which has received Breakthrough Therapy designation. The drug showed promising Phase 1b results with a 77% relative risk reduction in bloodstream infections in patients undergoing allogeneic hematopoietic stem cell transplant (allo-HSCT).
Eric Shaff, who led Seres for a decade and achieved the first-ever FDA-approved oral microbiome therapy, will remain on the company's Board of Directors.
Seres Therapeutics (NASDAQ:MCRB) ha annunciato un'importante transizione nella leadership: Thomas DesRosier e Marella Thorell sono stati nominati co-CEO, a partire dal 31 luglio 2025, in seguito all'uscita dell'attuale CEO Eric Shaff. Entrambi manterranno i loro ruoli attuali rispettivamente come Chief Legal Officer e Chief Financial Officer.
L'azienda sta attivamente collaborando con diverse parti per potenziali sviluppi commerciali e partnership, al fine di assicurare capitali aggiuntivi per il progresso di SER-155, che ha ottenuto la designazione di Breakthrough Therapy. Il farmaco ha mostrato risultati promettenti nella fase 1b con una riduzione del rischio relativo del 77% nelle infezioni del flusso sanguigno in pazienti sottoposti a trapianto di cellule staminali ematopoietiche allogeniche (allo-HSCT).
Eric Shaff, che ha guidato Seres per un decennio e ha ottenuto la prima terapia orale per il microbioma approvata dalla FDA, resterà nel Consiglio di Amministrazione dell'azienda.
Seres Therapeutics (NASDAQ:MCRB) anunció una importante transición en su liderazgo: Thomas DesRosier y Marella Thorell han sido nombrados co-CEOs, con efecto a partir del 31 de julio de 2025, tras la salida del actual CEO Eric Shaff. Ambos ejecutivos conservarán sus roles actuales como Director Legal y Director Financiero, respectivamente.
La compañía está en conversaciones activas con varias partes para posibles desarrollos comerciales y asociaciones que aseguren capital adicional para avanzar con SER-155, que ha recibido la designación de Terapia Innovadora (Breakthrough Therapy). El fármaco mostró resultados prometedores en la fase 1b con una reducción relativa del riesgo del 77% en infecciones en el torrente sanguíneo en pacientes sometidos a trasplante alogénico de células madre hematopoyéticas (allo-HSCT).
Eric Shaff, quien lideró Seres durante una década y logró la primera terapia oral para el microbioma aprobada por la FDA, permanecerá en la Junta Directiva de la empresa.
Seres Therapeutics (NASDAQ:MCRB)는 중요한 리더십 변화를 발표했습니다. Thomas DesRosier와 Marella Thorell이 2025년 7월 31일부터 공동 CEO로 임명되며, 현재 CEO인 Eric Shaff는 물러납니다. 두 임원은 각각 최고법률책임자(Chief Legal Officer)와 최고재무책임자(Chief Financial Officer) 역할을 계속 유지할 예정입니다.
회사는 SER-155의 개발 진전을 위해 추가 자본을 확보하기 위해 여러 파트너와 사업 개발 및 파트너십을 적극적으로 모색하고 있습니다. 이 약물은 획기적 치료제(Breakthrough Therapy) 지정을 받았으며, 동종 조혈모세포 이식(allo-HSCT)을 받는 환자들의 혈류 감염 위험을 상대 위험도 77% 감소시키는 유망한 1b상 결과를 보였습니다.
10년간 Seres를 이끌며 FDA 최초 승인 경구용 마이크로바이옴 치료제를 성공시킨 Eric Shaff는 회사 이사회에 남아 활동할 예정입니다.
Seres Therapeutics (NASDAQ:MCRB) a annoncé une transition majeure dans sa direction : Thomas DesRosier et Marella Thorell sont nommés co-CEO à compter du 31 juillet 2025, suite au départ de l'actuel CEO Eric Shaff. Les deux dirigeants conservent leurs fonctions actuelles respectivement de Chief Legal Officer et Chief Financial Officer.
L'entreprise est activement en discussion avec plusieurs parties pour des opportunités de développement commercial et de partenariats afin d'assurer des financements supplémentaires pour faire avancer SER-155, qui a obtenu la désignation de thérapie révolutionnaire (Breakthrough Therapy). Le médicament a montré des résultats prometteurs en phase 1b avec une réduction relative du risque de 77% des infections sanguines chez des patients ayant subi une greffe de cellules souches hématopoïétiques allogéniques (allo-HSCT).
Eric Shaff, qui a dirigé Seres pendant dix ans et obtenu la première thérapie orale microbiome approuvée par la FDA, restera membre du conseil d'administration de la société.
Seres Therapeutics (NASDAQ:MCRB) gab einen bedeutenden Führungswechsel bekannt: Thomas DesRosier und Marella Thorell werden ab dem 31. Juli 2025 als Co-CEOs eingesetzt, nachdem der aktuelle CEO Eric Shaff das Unternehmen verlässt. Beide Führungskräfte behalten ihre bisherigen Positionen als Chief Legal Officer bzw. Chief Financial Officer.
Das Unternehmen führt aktiv Gespräche mit verschiedenen Partnern, um potenzielle Geschäftsentwicklungen und Partnerschaften zu fördern und zusätzliches Kapital für die Weiterentwicklung von SER-155 zu sichern, das den Status einer Breakthrough Therapy erhalten hat. Das Medikament zeigte vielversprechende Phase-1b-Ergebnisse mit einer relativen Risikoreduktion von 77% bei Blutstrominfektionen bei Patienten, die eine allogene hämatopoetische Stammzelltransplantation (allo-HSCT) erhalten.
Eric Shaff, der Seres ein Jahrzehnt lang leitete und die erste von der FDA zugelassene orale Mikrobiomtherapie erreichte, wird im Vorstand des Unternehmens bleiben.
- SER-155 achieved Breakthrough Therapy designation for reducing bloodstream infections
- Phase 1b study showed 77% relative risk reduction in bloodstream infections
- Company secured first-ever FDA approval for oral microbiome therapy
- Active engagement with multiple parties for potential partnerships and funding
- CEO departure signals potential leadership uncertainty
- Company needs additional capital to advance clinical pipeline
- Dual CEO structure may create operational challenges
Thomas DesRosier and Marella Thorell, accomplished biopharma executives, appointed co-CEOs; Eric Shaff stepping down as CEO and will remain a Director on the Seres Board
Seres engaging with multiple parties regarding various deal structures, including potential business development and partnerships, intended to secure additional capital and other resources to enable the clinical advancement of SER-155 and additional live biotherapeutic product candidates
CAMBRIDGE, Mass., July 22, 2025 (GLOBE NEWSWIRE) -- Seres Therapeutics, Inc. (Nasdaq: MCRB), (Seres or the Company), a leading live biotherapeutics company, today announced the appointment of Thomas DesRosier and Marella Thorell as co-Chief Executive Officers. This appointment will follow the departure of Chief Executive Officer Eric Shaff on July 31, 2025, after a decade with the Company, to pursue a new professional opportunity. Mr. Shaff will continue to serve as a Director on the Seres Board. Mr. DesRosier and Ms. Thorell will retain responsibilities related to their roles as Chief Legal Officer and Chief Financial Officer, respectively.
"We are excited by the opportunities for Seres, highlighted by the potential of SER-155 to provide meaningful therapeutic benefit across multiple patient populations at high risk of serious bloodstream infections (BSIs), as well as additional pipeline assets for inflammatory and immune diseases, including ulcerative colitis and Crohn’s disease," said Thomas DesRosier and Marella Thorell, co-CEOs of Seres. "SER-155, which was granted Breakthrough Therapy designation for the reduction of BSIs in adults undergoing allo-HSCT, and Seres’ broader portfolio of live biotherapeutics represent substantial therapeutic and commercial opportunities. Engagements with several parties are underway regarding various deal structures, including potential business development and partnership opportunities, aimed at securing additional capital and support for continued advancement of our pipeline. We are working with focus and urgency, leveraging our collective transaction and capital sourcing experiences, to enable the clinical progression of SER-155 and deliver value for patients and shareholders.”
Further development of SER-155 is supported by previously disclosed Phase 1b placebo-controlled study results that showed a significant reduction (
"Tom and Marella are highly experienced and accomplished biopharma executives with a deep understanding of Seres and its unique and powerful live biotherapeutics platform capabilities, and they are well-positioned to shape the strategy and lead the Company," said Stephen Berenson, Chairman of Seres’ Board of Directors. "On behalf of the Board, we would like to thank Eric for his significant contributions to the Company over the past decade. During his tenure, Seres has dramatically advanced the field and successfully delivered the first-ever FDA-approved oral microbiome therapy to patients. We are pleased to continue to benefit from Eric’s perspective as a member of the Seres Board."
Eric Shaff commented: "It has been a privilege to lead the talented Seres team throughout a period of meaningful scientific and clinical advances. We have led the evolution of the live biotherapeutic field from an early scientific idea to a first-ever FDA approval and obtaining highly promising SER-155 results, suggesting the potential to transform the management of entirely new patient categories. I am exceptionally proud of the difference we have made in the lives of patients, and I am thrilled to continue working with Marella, Tom, and the entire team as they move the Company’s strategy forward, endeavoring to bring groundbreaking medicines to patients.”
Biographies for Mr. DesRosier and Ms. Thorell
Thomas J. DesRosier joined Seres in May 2016 as Executive Vice President, Chief Legal Officer and Secretary of Seres. Prior to joining Seres, he served as Chief Legal and Administrative Officer at ARIAD Pharmaceuticals, and prior to that, held the same position at Cubist Pharmaceuticals, where he led the negotiation of the acquisition of Cubist by Merck. Previous to that, he served as Senior Vice President and General Counsel, North America of Sanofi, a position he assumed in 2011 after Sanofi acquired Genzyme Corporation, where he was Senior Vice President and Chief Legal Officer. Earlier, Mr. DesRosier held senior legal positions at Wyeth Pharmaceuticals, and E.I. DuPont de Nemours. Mr. DesRosier serves on the board of directors of Avanir Pharmaceuticals. He received his B.A. in chemistry from the University of Vermont and his J.D. from Wake Forest University School of Law.
Marella Thorell joined Seres in March 2024 as Executive Vice President and Chief Financial Officer. She is a seasoned finance and operations expert with over 25 years of experience leading capital strategy, financial planning, accounting operations, building organizations and preparing and executing IPOs. Most recently, Ms. Thorell served as the Chief Financial Officer of Evelo Biosciences. Prior roles include Chief Accounting Officer at Centessa Pharmaceuticals, Chief Financial Officer of Palladio Biosciences, and Chief Financial Officer and Chief Operating Officer of Realm Therapeutics. Ms. Thorell began her career at Ernst & Young, LLP, and later worked for Campbell Soup Company. She holds a B.S. in Business from Lehigh University. Ms. Thorell is a Director and Chair of the Audit Committee of both ESSA Pharmaceuticals and Carisma Therapeutics.
About Seres Therapeutics
Seres Therapeutics, Inc. (Nasdaq: MCRB) is a clinical-stage company focused on improving patient outcomes in medically vulnerable populations through novel live biotherapeutics. Seres led the successful development and approval of VOWST™, the first FDA-approved orally administered microbiome therapeutic, which was sold to Nestlé Health Science in September 2024. The Company is developing SER-155, which has received Breakthrough Therapy designation for the reduction of bloodstream infections in adults undergoing allo-HSCT and Fast Track designation for reducing the risk of infection and graft-versus-host disease in adults undergoing allo-HSCT, and which has demonstrated a significant reduction in bloodstream infections and related complications (as compared to placebo) in a Phase 1b clinical study in patients undergoing allo-HSCT. SER-155 and the Company's other pipeline programs are designed to target multiple disease-relevant pathways and are manufactured from standard clonal cell banks via cultivation, rather than from the donor-sourced production process used for VOWST. In addition to allo-HSCT, the Company intends to evaluate SER-155 and other cultivated live biotherapeutic candidates in other medically vulnerable patient populations including autologous-HSCT patients, cancer patients with neutropenia, CAR-T recipients, individuals with chronic liver disease, solid organ transplant recipients, as well as patients in the intensive care unit and long-term acute care facilities. For more information, visit www.serestherapeutics.com.
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 statements about: executive transitions; the results of our clinical studies and data readouts; clinical development plans and commercial opportunities; operating plans and our future cash runway; our ability to secure a partnership and/or other business development transaction, and/or generate or obtain additional capital or financing; our planned strategic focus; anticipated timing of any of the foregoing; and other statements that 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: (1) our need for additional funding; (2) our ability to continue as a going concern; (3) we have incurred significant losses, are not currently profitable and may never become profitable; (4) our history of operating losses; (5) the expected payments from the VOSWT sale are subject to risks and uncertainties; (6) we may not be able to realize the anticipated benefits of the VOWST sale, and may face new challenges as a smaller, less diversified company; (7) we have in the past and may in the future receive notice of the failure to satisfy a continued listing rule from The Nasdaq Stock Market LLC; (8) our novel approach to therapeutic intervention; (9) our reliance on third parties to conduct our clinical trials and manufacture our product candidates; (10) our ability to achieve market acceptance necessary for commercial success; (11) the competition we will face; (12) our ability to protect our intellectual property; and (13) 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 May 7, 2025, 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.
Investor and Media Contact:
IR@serestherapeutics.com
Carlo Tanzi, Ph.D.
Kendall Investor Relations
ctanzi@kendallir.com
FAQ
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